Potato-leek Soup Recipe

Prepare and clean leeks

Trim root ends and dark green tops from leeks, reserving only white and light green parts. Slice leeks in half lengthwise, then thinly slice crosswise. Rinse thoroughly in a bowl of cold water, separating rings to remove grit. Drain and pat dry.

Prep potatoes and aromatics

Peel potatoes and cut into roughly 1-inch cubes for even cooking. Peel and finely chop the yellow onion. Mince garlic cloves.

Sweat vegetables

In a large heavy-bottomed pot, heat butter and 1 tablespoon olive oil over medium heat until butter foams. Add the sliced leeks and chopped onion with a pinch of salt. Cook gently, stirring occasionally, until softened and translucent, about 8–10 minutes—do not brown. Add minced garlic and cook 30–45 seconds until fragrant.

Add potatoes and simmer

Stir in the potato cubes, then add the stock, bay leaf and thyme sprigs. Bring to a gentle simmer over medium-high heat, then reduce heat to maintain a low simmer. Cook uncovered until potatoes are very tender, about 15–20 minutes.

Remove aromatics and blend

Remove and discard the bay leaf and thyme sprigs. Using an immersion blender, puree the soup until smooth and velvety. Alternatively, carefully transfer soup in batches to a blender and purée, returning it to the pot.

Finish with milk and cream

Stir in the whole milk and heavy cream. Warm gently over low heat—do not boil—until hot and slightly thickened, about 3–5 minutes. Taste and season with the remaining salt and freshly ground black pepper. If desired, stir in the optional teaspoon of lemon juice to brighten flavors. Keep warm while you make croutons.

Adjust texture (optional)

If the soup is too thick, thin with up to 120 ml (1/2 cup) additional stock or milk, adding a little at a time until desired consistency is reached.

Finish and serve

Ladle soup into warmed bowls. Sprinkle a generous pinch of snipped chives over each bowl. Place a spoonful of Grana Padano croutons on top or to the side.

Preheat oven

Preheat oven to 200°C (400°F). Line a baking sheet with parchment paper or a silicone baking mat.

Toss bread cubes

In a medium bowl, toss the bread cubes with 2 tablespoons olive oil, sea salt and freshly ground black pepper until evenly coated.

Bake and add cheese

Spread bread cubes in a single layer on the prepared baking sheet. Bake for 8 minutes, then remove from oven and sprinkle the grated Grana Padano evenly over the hot cubes. Return to the oven and bake an additional 4–6 minutes, or until croutons are golden brown and cheese is melted and crisp. Watch closely to avoid burning.

Cool and crisp

Remove croutons from oven and let cool on the sheet for 5 minutes to crisp further. Transfer to a bowl; they will continue to harden as they cool.