We’ve had a cool August in Berlin, and I find myself thinking about recipes that have been on a summer hiatus. Stewed lentils. Mac & cheese. Braised vegetables. And of course soup. A deep bowl of hot soup and a heavily buttered slice of toast hits the spot. This soup is everything I want, the salty leeks doing the work that chicken bones might, and the potatoes collapsing into their softness. I tried leaving the skins on the potatoes once and can confirm that it is much better without, but as always, make the tweaks that suit you.
Leek & potato soup
800 g waxy potatoes, peeled & roughly chopped
200 g floury potatoes, peeled & roughly chopped
2 large leeks, thoroughly washed & sliced
40 g unsalted butter
4 tbsp olive oil
2.5–3 tsp salt (depending on taste)
2-2.5 litres of water
In a very large pot (I use a 9-litre pot), melt the butter with the olive oil over a medium heat. When it’s hot, add the potatoes, leeks, and one teaspoon of the salt. Mix everything together; once it’s all sizzling, cover with a lid and reduce the heat to low. Allow to sweat for 15 minutes on a low heat. You can stir it once or twice to make sure it isn’t sticking to the bottom, but replace the lid.
Add the water plus one more teaspoon of salt. Stir everything together and taste the water. I like my soup quite salty, so I would almost certainly add the full third teaspoon of salt, but if you like it less so, adjust to your taste. Maybe half a teaspoon (or even less) would do for you.
Bring to a boil and cook on a medium heat for another 15 minutes. Towards the end use a potato masher to lightly mash some of the potatoes (not all of them, you want some chunky texture). This helps thicken up your broth a bit.
You can serve immediately, but the flavour of this soup really benefits from a night in the fridge. Just heat up the next day and eat with plenty of buttered toast or even a grilled cheese sandwich.