I find potatoes in all forms, from fluffy mash to dripping-soaked chips, supremely comforting, but there’s little that hits the spot more effectively on a dreary day than velvety potato soup shot through with the sweet heat of leeks. This version freezes well, ready for emergencies; I bake extra potatoes while making it and have them for lunch. As I said, I just love spuds.
Prep 15 min
Cook 90 min
Serves 4
About 375g floury potatoes, preferably large baking potatoes
2 generous tbsp butter or oil
450g trimmed leeks (about 3 medium ones)
Salt
1 litre light chicken stock, or vegetable stock or water
4 tbsp creme fraiche, or soured cream, to serve (optional)
1 small bunch chives, to serve
1 A note on the potatoes
Try to find large baking potatoes for this, because you’ll get more flesh and less skin than with smaller ones. Floury varieties such as rooster, king edward and desiree are ideal, though an all-rounder such as maris piper will also work fine. Heat the oven to 200C (180C fan)/390F/gas 6. Scrub the potatoes clean, if necessary.
2 Bake the potatoes
Prick the potatoes several times with a fork or skewer, to insure against the rare but traumatic possibility of explosion, then bake for about 75 minutes, or until cooked through but not too crisp. The exact timing will depend on their size, so if they’re relatively small, begin checking them with a skewer after about 45 minutes. Remove and leave to cool slightly.
3 Prep the leeks
While the potatoes are cooking, trim any tough-looking green leaves off the very tops of the leeks, then cut them all in half lengthways from the top down, but not all the way to the bottom, so they’re still held together at the base. Rinse well under cold water, fanning out the sliced leaves to get rid of any lurking grit. Shake the leeks dry, then roughly chop, discarding the root ends.
4 Sweat the leeks until soft
Melt the butter in a large saucepan over a gentle heat – if you’d prefer to keep this plant-based, you could use oil instead, because, thanks to the richness of the potato, this works very well as a vegan soup, too. Drop the chopped leeks into the hot fat, add a good pinch of salt and fry, stirring occasionally so they don’t catch and brown, until soft and silky.
5 Add the chopped baked potatoes
Once the potatoes are cool enough to handle (if you want to speed up that process, cut them in half when they come out of the oven), cut them, skins and all, into rough cubes. Scoop a generous spoonful of the softened leeks out of the pan and set aside for later, then add the potatoes to the pan and saute with the remaining leeks for another couple of minutes.
6 Pour in the stock
Pour in the stock – I find chicken stock the most neutrally savoury option here, but vegetable, pork or smoked fish stock would also work if you want to take the soup in another direction, as would just plain water.
Bring to a simmer and cook for about 10 minutes.
7 Cool, then blitz
If you’re using a jug blender, take the pan off the heat, leave the soup to cool slightly, then whizz to a smooth puree; if you’re using a stick blender, you can puree it straight away, but I’d still advise taking it off the heat just to be on the safe side. If at this stage the soup is too thick for your liking, thin it with a little more liquid; if it’s too watery, the soup can be reduced further in the pan.
8 Finishing touches
Check the seasoning and adjust as necessary – this is also the time to add a little extra spice, if you like. I often finish my leek and potato soup with grated nutmeg, but cayenne pepper, a mild curry powder or a few caraway seeds would all be delicious, too, as would some finely grated lemon zest. Stir in the reserved sauteed leeks.
9 Garnish and tuck in
Divide between bowls, then top each serving with a tablespoon of creme fraiche, if using. Finely chop the chives, then scatter over the top. To make the soup more substantial, you could also stir in some flaked smoked fish (trout or mackerel, for example), fried bacon lardons, cooked mussels, hard-boiled eggs or crisp shallots. I like my soup with brown bread and butter.
