Leek & Potato Soup Recipe

Prepare aromatics

Trim leeks: discard root and tough dark green tops, halve lengthwise, rinse under running water to remove grit, then thinly slice the white and light green parts until you have approximately 3 cups. Dice the onion and peel and dice potatoes into 1/2-inch pieces so they cook evenly.

Melt butter in a large heavy-bottomed pot over medium heat. Add the diced onion and a pinch of salt and sweat for 5–6 minutes until translucent but not browned.

Add the sliced leeks and continue to cook, stirring occasionally, for 6–8 minutes until softened and fragrant. Add the minced garlic and cook for 30–60 seconds until aromatic.

Add the diced potatoes, thyme leaves, bay leaf, and pour in the stock. Increase heat to bring to a gentle boil, then reduce to a simmer. Cook uncovered for 15–20 minutes, or until potatoes are very tender when pierced with a fork.

Remove and discard the bay leaf. Using an immersion blender, purée the soup until mostly smooth but still slightly textured. Alternatively, transfer in batches to a blender (do not overfill) and purée, returning soup to the pot.

Stir in the milk or half-and-half and warm gently over low heat—do not boil. Taste and adjust seasoning with salt and freshly ground black pepper. If the soup is thicker than you like, thin with up to 1/2 cup additional stock or milk to reach desired consistency.

Finish with a drizzle (about 1 tsp) of olive oil and stir in half of the chopped chives or parsley. Keep warm while you prepare croutons and bread.

Preheat oven to 375°F (190°C). Line a baking sheet with parchment or lightly oil it.

In a large bowl, toss sourdough cubes with olive oil, melted butter, chopped parsley, chopped thyme, garlic powder, salt, and black pepper until evenly coated.

Spread the coated bread cubes in a single layer on the prepared baking sheet. Bake for 10–14 minutes, stirring once halfway through, until croutons are golden and crisp. Remove from oven and let cool slightly. Reserve a small handful of croutons for garnish.

If serving extra slices of sourdough, warm them in the oven for 3–5 minutes or toast as desired just before serving.

To serve: ladle soup into warmed bowls, top with remaining chopped chives or parsley, a drizzle of olive oil if desired, and scatter herb croutons on top or serve them on the side with slices of warmed sourdough.