Potato & Leek Soup
Potato and leek soup is a useful reminder that good soup doesn't necessarily require a stockpot full of ingredients. Here, most of the flavour comes from doing one very simple thing properly: cooking the leeks slowly in butter until they become soft, sweet and almost collapse into themselves, without letting them brown.
Potatoes provide the body, while milk and cream make everything richer without turning the soup unnecessarily heavy. A little white pepper, perhaps some nutmeg, and a generous splash of good olive oil at the end are really all it needs.
The only other bit of technique worth respecting is the blender. Potatoes are full of starch and don't appreciate being aggressively blitzed for several minutes.
Basically, cook the leeks slowly and blend the potatoes quickly. The soup will handle the rest.
Ingredients
3 medium sized leeks
150 g onions, sliced
400 g potatoes, peeled and diced
30 g butter
2 garlic cloves, finely chopped
1 bay leaf
750 ml light stock or water
150 ml milk
75 ml cream
1 tsp salt, or to taste
¼–½ tsp white pepper
Small pinch nutmeg (optional)
Chives, spring onion greens or finely sliced leek greens, to garnish
Extra virgin olive oil and crème fraîche, to finish (optional)
Method
Clean the leeks
Remove the deep dark stalk, root and split the white and light green core lengthwise and rinse thoroughly between the layers to remove any trapped grit. Drain well and slice fairly thinly.
Slowly cook the leeks and onion
Melt the butter in a saucepan over medium-low heat. Add the sliced leeks, sliced onion and a pinch of salt.
Cook gently for 8–10 minutes, stirring occasionally, until the leeks are completely soft and sweet but have taken on no colour. Don't rush this stage. Much of the soup's flavour comes from allowing the leeks to cook slowly without browning.
Add the garlic and cook for another 1 minute.
Cook the potatoes
Add the diced potatoes, bay leaf and stock. Bring to a gentle boil, then reduce the heat to a simmer.
Partially cover and cook for 15–20 minutes, or until the potatoes are completely tender and easily crushed with a spoon.
Blend the soup
Remove and discard the bay leaf.
Blend the soup until smooth, but stop as soon as you reach the desired texture. Overworking cooked potatoes can make the soup gluey.
If using a countertop blender, work carefully with the hot liquid. Leave the vent open and cover it loosely with a kitchen towel to allow steam to escape.
Add the dairy
Return the blended soup to low heat. Stir in the milk and cream, followed by the white pepper and nutmeg, if using.
Warm gently for 3–4 minutes without allowing the soup to boil vigorously.
Taste and adjust the salt.
Finish and serve
Ladle into bowls and finish with a generous drizzle of extra virgin olive oil, a dollop of crème fraîche and chopped chives, spring onion greens or finely sliced leek greens.
Getting the consistency right
The soup should be creamy and silky but still easily pourable, rather than resembling potato purée.
If it is thicker than you prefer after blending, gradually add 50–150 ml hot stock or milk until you reach the desired consistency.