Rustic Browned Leek and Potato Soup

Trim the tough dark green tops and roots from the leeks, split the pale stalks lengthwise, slice into 1 cm half-moons, and submerge in a colander in cold water to wash away all grit before draining.

Peel the Yukon Gold potatoes with a peeler and dice into uniform 1.5 cm cubes.

Place the Dutch oven over medium heat at 160°C (320°F), add the unsalted butter and olive oil, and heat until the butter melts and foams gently.

Add the sliced leeks and 2 g of fine sea salt to the pot, stirring occasionally with a wooden spoon over medium heat for 12 to 14 minutes until deeply golden, caramelized, and sweet.

Stir the minced garlic into the caramelized leeks and sauté for 60 seconds until fragrant and lightly softened.

Add the diced potatoes, vegetable broth, fresh thyme sprigs, bay leaf, and the remaining 4 g of fine sea salt; bring to a boil, then reduce heat to maintain a steady simmer at 95°C (203°F) for 16 to 18 minutes until the potatoes are easily pierced with a fork.

Turn off the heat, discard the bay leaf and spent thyme stems, and use a potato masher directly in the pot to crush approximately one-third of the potato cubes to thicken the broth while preserving prominent soft potato pieces.

Stir in the freshly cracked black pepper, taste the soup, and adjust with additional salt if needed.

Ladle the hot soup into warmed bowls, drizzle each serving with 15 ml of heavy cream if desired, and scatter the minced fresh chives over the top before serving.