Soups & Stews
This Au Bon Pain potato leek soup recipe delivers the same velvety, restaurant-quality texture you crave at home—silky smooth with a perfect balance of earthy leeks and creamy potatoes. The secret lies in slow-cooked leeks and a proper velouté base that transforms simple ingredients into something luxurious.
I've perfected this version after years of testing, ensuring every spoonful is rich, flavorful, and impossibly tender.
The process begins with gently sautéing leeks until they're soft and sweet, then building a velouté base that forms the soup's velvety foundation. Potatoes simmer until fork-tender, creating that signature creamy consistency without needing heavy cream.
What sets this apart is the finishing touch—a sprinkle of toasted garlic croutons that add irresistible crunch to every bite.
What you'll end up with is a soup so smooth it practically melts in your mouth, with layers of savory leek flavor and just the right amount of creaminess. The aroma alone will have everyone gathering around the pot, and the texture—creamy yet light—makes it perfect for chilly days.
This recipe serves 6 and takes about 1 hour, including prep time.
Serve it with crusty bread on the side or a sprinkle of fresh chives for color and freshness. The best part? Leftovers taste even better the next day as flavors deepen. Let's make this soup that'll have everyone asking for seconds.
Ingredients for au bon pain potato leek soup
Velvety leeks, creamy potatoes, and toasted garlic crunch—this is the perfect balance for Au Bon Pain-inspired soup.
| Ingredient | Amount | Notes |
|---|---|---|
| Yellow Onions 🧅 | 1 whole | Diced, white part only |
| Leeks 🧅 | 3 large | White and light green parts, sliced |
| Russet Potatoes 🥔 | 2 lbs | Peeled, cut into 1-inch chunks |
| Celery Stalks 🥬 | 3 medium | Diced, leafy parts removed |
| Garlic Cloves 🧄 | 4 cloves | Minced for velouté base |
| All-Purpose Flour 🌾 | ¼ cup | For velouté base |
| Chicken Stock 💧 | 4 cups | Low-sodium preferred |
| Whole Milk 🥛 | 1 cup | Full-fat for creaminess |
| Heavy Cream 🥛 | ½ cup | For velvety finish |
| Sourdough Bread 🍞 | 1 loaf | Crust removed, cubed |
| Extra-Virgin Olive Oil 🫒 | ½ cup | For sautéing and finishing |
| Salt 🧂 | 1 ½ tsp | Kosher or sea salt |
| Black Pepper 🌶️ | ½ tsp | Freshly ground preferred |
| Fresh Thyme 🌿 | ¼ cup | Leaves only, chopped |
| Fresh Chives 🌿 | 0.1 cup | Chopped for garnish |
The leeks are the star here—look for bright white and light green parts, no yellowing. Whole Foods or Trader Joe's usually have the freshest. If you can't find sourdough, a crusty baguette works too—just cube it and dry it out in the oven first for better toasting. The Russet potatoes are non-negotiable for that creamy texture; Yukon Golds work too, but Russets hold up better to long simmering. For the stock, Pacific Foods or Swanson low-sodium are my go-tos—they add depth without overpowering saltiness.
No fresh thyme? Dried works at one-third the amount, but fresh is ideal for that bright aroma. Running low on heavy cream? Half-and-half plus a splash of milk gets you close. The flour needs to be all-purpose; bread flour gets too gummy. For the garlic croutons, toast the bread cubes in olive oil until golden—don't skip this step, it's what makes this soup restaurant-quality. If you're in a pinch, store-bought garlic croutons from the deli section work, but they won't be as fresh-tasting.
This soup tastes even better the next day—flavors meld beautifully. Store leftovers in airtight containers for 4-5 days in the fridge. For freezing, portion into containers and freeze for up to 3 months. The croutons can be toasted fresh and added back when reheating, or you can freeze them separately and toast them straight from frozen. I always make a double batch—one for dinner, one for lunch the next day—because it disappears fast.
Why You'll Love This Recipe
- I swear by this trick: buy pre-sliced leeks and celery—just rinse the leeks well—and halve the onions. The garlic? Smash it with the flat of a knife instead of mincing. Ten minutes saved, same rich flavor.
- No-Chop Shortcuts: I swear by this trick: buy pre-sliced leeks and celery—just rinse the leeks well—and halve the onions. The garlic? Smash it with the flat of a knife instead of mincing. Ten minutes saved, same rich flavor.
- Creamy Without Guilt: That velvety texture comes from just potatoes, leeks, and a splash of cream at the end—not heavy cream, but a light pour. The Russets break down perfectly, and the onions caramelize just enough to add depth without overpowering.
- Weeknight to Party: Same soup, different vibes. Serve it with crusty bread for a lazy Sunday, or top it with crispy bacon and a sprinkle of parsley for dinner guests. The base is always foolproof, so I never stress about what to pair.
Step-by-step instructions for Au Bon Pain potato leek soup
Here's how to create that iconic velvety soup with a toasted garlic crunch—just like the bakery version.
Build the Velouté Base
Heat the 0.5 cup extra-virgin olive oil in a large Dutch oven over medium heat until shimmering. Add the diced 1 whole yellow onion and sliced 3 large leeks (white and light green parts only), cooking for 8-10 minutes until softened and golden. This slow cook time develops their natural sweetness.
Stir in the diced 3 medium celery stalks and cook for another 3 minutes until fragrant. Sprinkle the 0.25 cup all-purpose flour over the vegetables and stir vigorously for 2 minutes to toast the flour and remove any raw taste. This creates the velouté base that will thicken our soup beautifully.
Develop the Flavor Foundation
Pour in the 4 cups chicken stock and bring to a gentle simmer. Add the 2 lbs peeled russet potatoes (cut into 1-inch chunks) and 4 minced garlic cloves. Stir well, then reduce heat to low-medium and let simmer uncovered for 15 minutes until the potatoes are fork-tender.
While simmering, add the 0.25 cup chopped fresh thyme and 1.5 tsp salt. Taste the broth—it should be flavorful but not salty. If needed, adjust seasoning with more salt or a pinch of black pepper. The potatoes should be soft enough to mash slightly between your fingers but still hold their shape.
Create the Signature Creamy Texture
Using an immersion blender, carefully blend the soup directly in the pot until completely smooth. For a perfect texture, strain through a fine-mesh sieve if you prefer extra silky consistency. Return the soup to the pot and stir in the 1 cup whole milk and 0.5 cup heavy cream.
Simmer gently for another 5 minutes to let the dairy flavors meld with the vegetables. The soup should now be luxuriously velvety with no lumps. Taste again and adjust seasoning if needed—this is your chance to perfect the balance of flavors before adding the final touches.
Toast the Garlic Crunch
While the soup simmers, heat a small skillet over low heat and add 2 tablespoons extra-virgin olive oil. Add the remaining 2 minced garlic cloves and toast gently for 1-2 minutes until golden brown but not burned. This creates the signature toasted garlic flavor that elevates the soup.
Remove the skillet from heat and set aside. Cut the 1 loaf sourdough bread into ½-inch cubes, removing the crust. Toss the bread cubes with the toasted garlic and any remaining oil in the skillet, stirring gently to coat. Spread on a baking sheet and toast in a 375°F oven for 8-10 minutes until golden and crisp.
Assemble and Serve
Ladle the warm soup into bowls, dividing evenly among the 6 servings. Top each portion with a generous sprinkle of toasted sourdough cubes and 0.1 cup chopped fresh chives. The contrast of creamy soup with crispy bread and fresh herbs makes this soup truly exceptional.
Serve immediately with a drizzle of the remaining extra-virgin olive oil and an extra pinch of black pepper. The toasted garlic flavor will permeate every bite, creating that signature Au Bon Pain experience. Enjoy with a side of crusty bread for dipping!
Pro Tips For Making Au Bon Pain Potato Leek Soup
- SWEEP THE LEEK GREENS: If you’re not scrubbing those leeks like you’re washing dishes for a picky dinner guest, you’ll end up with gritty soup. Split them lengthwise, rinse under cold water, and scrub the whites and pale greens with your fingers—no need to peel unless they’re truly muddy. (Yes, even the greens add flavor, but only if they’re clean.)
- SWEAT THE ONIONS LOW: I used to rush this step, and the onions would either burn or taste raw. Instead, keep the heat at a steady medium and let them cook for 8–10 minutes until they’re translucent and just starting to soften. A splash of water or a pinch of salt helps release their sweetness—don’t skip it.
- CUT POTATOES EVENLY: Russets break down unevenly if they’re not uniform. Aim for 1-inch chunks, and if some pieces look lumpy, trim them—no one wants a mouthful of undercooked potato. (Pro move: Save the scraps for mash or fries while you’re at it.)
- BLITZ THE SOUP: After simmering, don’t let it sit idle—blend it hot in batches for silky texture. If you blend cold, the potatoes turn gummy. Pulse first, then blend fully, and stir immediately to distribute the creaminess. (And yes, a hand blender is worth the splurge for this.)
Storing and reheating your leftovers
Refrigerator Storage
Let your soup cool to room temperature for about 30 minutes before transferring to airtight containers—I use glass Pyrex with snap-on lids for best results. Store in the fridge at 40°F or below for up to 4-5 days, though I find the flavors actually deepen overnight.
The croutons should be added fresh when reheating, as they lose crispness when stored. 🥣
Freezer Storage
This soup freezes beautifully for up to 3 months if stored properly. Portion into quart-sized freezer bags, leaving 1-inch headspace for expansion. Remove as much air as possible to prevent freezer burn.
For best texture, freeze the soup without the croutons—add them fresh when reheating. I like to freeze individual meal portions so I can grab just what I need. ❄️
Stovetop Reheating
My preferred method is stovetop reheating because it preserves that velvety texture. Pour soup into a pot and heat over medium-low heat, stirring occasionally, until warmed through (10-15 minutes).
If it looks too thick after reheating, add 1-2 tablespoons of water or milk to restore creaminess. Always add fresh croutons after reheating for that perfect crunch. 🔥
Microwave Reheating
For quick reheating, transfer soup to a microwave-safe bowl and cover loosely with a microwave-safe lid. Heat on medium power (50%) in 1-minute intervals, stirring between each, until heated through (3-4 minutes total).
Avoid high power to prevent skin formation. The croutons can be toasted separately in a dry skillet while the soup reheats. 💫
Crouton Refresh
If you froze the croutons separately, toast them straight from frozen in a dry skillet over medium heat for 2-3 minutes until crispy. For extra flavor, add a pinch of garlic powder or smoked paprika while toasting.
Freshly toasted croutons make all the difference in that restaurant-quality texture. The key is keeping them separate until the very end. 🌟
Serving Seconds
This soup makes fantastic leftovers—double the batch if you're feeding a crowd! Store in individual portions so you can reheat just what you need. The velvety texture actually improves after refrigeration, making it perfect for lunch the next day.
I always keep a jar of fresh chives on hand to garnish reheated portions for that pop of color and freshness. 💛
Nutrition facts
Frequently asked questions
Can I make this potato leek soup without dairy?
Replace the 1 cup whole milk and 0.5 cup heavy cream with 1.5 cups unsweetened almond milk or coconut milk for a creamy texture. For extra richness, stir in 2 tablespoons nutritional yeast after blending. The velvety consistency comes from the potatoes and proper velouté base, so you won't sacrifice smoothness.
Why does my soup turn out too thin?
This usually happens if the potatoes overcook and break down too much during blending. For a thicker soup, simmer the potatoes for 12-15 minutes (not until mushy) and blend only until smooth—not pureed. If needed, stir in 1 tablespoon cornstarch mixed with 2 tablespoons cold water and simmer for 2 minutes to thicken. The velouté base should naturally provide enough body if cooked properly.
Can I use frozen leeks instead of fresh?
Fresh leeks are ideal for their sweetness, but frozen works in a pinch. Thaw them first, then pat dry thoroughly to prevent a watery soup. Use 4 large frozen leeks (about 1.5 cups sliced) and cook them for 5-7 minutes longer than fresh to remove excess moisture. The flavor won't be as bright, but the texture will still be great!
What’s the secret to the perfect velouté base?
The key is toasting the flour for 2 full minutes after adding it to the vegetables—this removes the raw taste and creates a rich, nutty flavor. Keep the heat at medium and stir constantly to prevent burning. The flour should turn a light golden color before adding the stock. This step transforms ordinary soup into something truly luxurious!
How can I make this soup spicier?
Add ½ teaspoon smoked paprika or ½ teaspoon cayenne pepper to the velouté base while cooking. For depth, stir in 1 teaspoon hot sauce or ½ teaspoon red pepper flakes at the end. For a smoky kick, toast 1 teaspoon cumin seeds in the olive oil with the leeks. Balance the heat with extra black pepper or a splash of cream if needed.