Potato and Leek Soup

Name: Potato and Leek Soup
Prep time: 20 min
Cook time: 30 min
Total time: 50 min
Cuisine: France
Ingredients: 40 g (3 tbsp) unsalted butter; 3 leeks, about 600 g untrimmed; white and pale green parts only, sliced and washed; 1 small onion, sliced; 500 g (1 lb 2 oz) floury potatoes (Russet, Maris Piper), peeled and sliced 1 cm; 1 l (4 cups) chicken or vegetable stock, Chicken Stock, Vegetable Stock or store-bought; 1 bay leaf; 100 ml (scant ½ cup) heavy cream or whole milk; 1 tbsp chives, finely snipped; fine sea salt and white or black pepper, about 8 g (1⅓ tsp) salt

Gently sweated leeks, floury potatoes and a light, smooth body

Serves: 4
Hands-on: 20 min
Total: 50 min
Level: Easy

Few ingredients, everything depending on technique: leeks cooked slowly in butter without color, potatoes simmered just until soft, and a blend that stops before the potatoes turn gluey. Serve it hot, or chill it into vichyssoise.

Ingredients

40 gunsalted butter (3 tbsp)
3leeksabout 600 g untrimmed; white and pale green parts only, sliced and washed
1small onionsliced
500 gfloury potatoes (Russet, Maris Piper) (1 lb 2 oz)peeled and sliced 1 cm
1 lchicken or vegetable stock (4 cups)Chicken Stock, Vegetable Stock or store-bought
1bay leaf
100 mlheavy cream or whole milk (scant ½ cup)
1 tbspchivesfinely snipped
fine sea salt and white or black pepperabout 8 g (1⅓ tsp) salt

Diet: Gluten-free
Allergens: milk, celery
Origin: France
Season: Autumn, Winter, Spring

Method

Slice the leeks, then swish them in a big bowl of cold water to release grit. Lift them out with your hands, leaving the grit behind, and drain.
Melt the butter in a heavy pot over medium-low heat. Add the leeks, onion and 3 g (½ tsp) salt. Cover and cook, stirring every few minutes, until very soft and sweet but not browned at all, 12–15 minutes. 13 min
Add the potatoes, stock and bay leaf. Bring to a simmer and cook until the potatoes break apart easily when pressed with a spoon, 15–20 minutes. 18 min
Remove the bay leaf. Blend with a stick blender in short pulses just until smooth, about 30 seconds — no longer.
Stir in the cream, reheat gently without boiling, and season with salt and pepper. Serve with chives on top.

Why it works

Sweating leeks slowly under a lid softens them and draws out sugars without browning, keeping the soup pale and sweet. Floury potatoes collapse and thicken the soup naturally. Over-blending bursts their starch cells and releases free starch, which turns the soup gluey, so a brief blend gives a smooth but light texture.

Common mistakes

Not washing the leeks after slicing: grit hides between the layers.
Using a high-speed blender for minutes: potatoes go gummy. Pulse briefly, or use a food mill.
Letting the leeks brown: you lose the clean, delicate flavor and pale color.

Variations

Vichyssoise: Chill the finished soup at least 4 hours; thin with a little cold milk, season again (cold food needs more salt) and serve with chives.
Chunky farmhouse: Don't blend; just crush some of the potatoes against the pot and add crisp bacon on top.

Make ahead and storage

Keeps 3 days in the fridge. Freezing makes potato soups grainy; it's edible but best fresh.

Notes

For a vegetarian version, use vegetable stock.