This humble yet elegant potato leek soup is a French classic. It’s simple to make, deeply comforting, and can be enjoyed hot or cold. In fact, when served chilled with cream, it takes on its famous alter ego, vichyssoise. With tender leeks, buttery potatoes, and a silky finish, it’s a recipe that feels timeless. Garnish with fresh herbs or serve with crunchy croutons for a dish that’s both rustic and refined.
INGREDIENTS:
3 medium leeks (white and tender green parts), split, washed, and thinly sliced
1 small brown onion, peeled, halved through the root, and finely sliced
4 medium potatoes (such as Carola), peeled, halved lengthwise, and sliced 1/4 inch thick
6 cups chicken or vegetable stock
2–3 tablespoons unsalted butter
Grapeseed or other neutral oil, as needed
Salt and white pepper, to taste
1/4 cup chervil leaves* or finely sliced chives
*Chervil has a delicate, anise-like flavor and is best cut with scissors. If unavailable, chives are an excellent substitute; a touch of finely minced tarragon can mimic chervil but use sparingly.
METHOD:
Heat a 3–4 quart pot over medium heat. Add a film of oil, then 1 tablespoon butter. When the butter foams, add leeks and onion. Stir to coat and cook gently, about 10 minutes, until softened but not browned. Reduce heat if necessary.
Add stock and potatoes. Stir to prevent sticking, then season lightly with salt and white pepper. Bring to a simmer and cook until potatoes are tender, 20–30 minutes.
Use an immersion blender to purée until smooth. Alternatively, carefully purée in batches in a blender (fill only 2/3 full, cover with a towel, and start on low to avoid splattering). For extra richness, blend in 2–3 tablespoons butter.
Taste and adjust seasoning. Stir in some chives (if using), reserving the rest to garnish. If using chervil, sprinkle leaves on top just before serving.
Ladle into warmed bowls and serve with croutons on the side.
CHEF NOTES:
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Add a cup of thinly sliced sorrel before puréeing; the heat will gently cook the leaves.
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Watercress or arugula can also be blended in for a peppery twist; drizzle with olive oil before serving.
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For a luxurious touch, add a drizzle of truffle oil and dust with powdered dried mushrooms.
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Cook leeks and onion in bacon fat, then serve topped with a cheddar-crusted crouton for a heartier version.
MAKE AHEAD:
Potato leek soup can be made up to 2 days in advance. Let it cool completely, then refrigerate in an airtight container. Reheat gently over low heat, adding a splash of stock or cream if needed to restore its silky texture. The flavors deepen overnight, making it even more delicious the next day.
YIELD: Serves 4 – 6
