Leek and Potato Soup
Leeks sweated under a lid until they give up their sugar, then potato and stock. Three ingredients, no browning anywhere.
- Prep
- 15m
- Cook
- 35m
- Total
- 50m
- Serves
- 4
- Effort
- Easy
Method
Tap a step number to mark it done. Tap an ingredient once for got it, twice for need it.
| 50 g | Sweat the leeks in butter under a lid, no colour at all 15m Browning gives a nutty flavour that fights the clean sweetness you want here. | Simmer until the potato collapses under a spoon 20m | Blend until smooth, then adjust with more stock and salt 5m Blend hot potato too long and it turns gluey. Thirty seconds is enough. | |
| 4 | ||||
| 1 tsp | ||||
| 3 sprigs | ||||
| 500 g | ||||
| 1 l | ||||
| 1 | ||||
| 150 ml | ||||
| 1/2 tsp | ||||
| a small bunch | ||||
-
Sweat the leeks in butter under a lid, no colour at all
15m- butter 50 g
- leeks 4
- salt 1 tsp
- thyme 3 sprigs
Browning gives a nutty flavour that fights the clean sweetness you want here.
-
Simmer until the potato collapses under a spoon
20m- from 1 Sweat the leeks in butter under a lid, no colour at all
- floury potatoes 500 g
- vegetable stock 1 l
- bay leaf 1
-
Blend until smooth, then adjust with more stock and salt
5m- from 2 Simmer until the potato collapses under a spoon
- whole milk 150 ml
- white pepper 1/2 tsp
- chives a small bunch
Blend hot potato too long and it turns gluey. Thirty seconds is enough.
Why the lid matters
Sweating is not gentle frying — it is steaming in the vegetable’s own liquid. The lid keeps that moisture in the pan, holding the leeks just below 100°C so they soften and their sugars concentrate without the surface ever drying enough to brown. Fifteen minutes of that produces a sweetness you cannot get back later. Floury potatoes then break down into the liquid and thicken it, which is why the soup needs no cream to feel substantial.
Notes
- Leeks trap grit between the layers. Slice first, then wash in a bowl of water and lift them out, leaving the sand behind.
- Blend briefly. Potato starch that has been sheared to death goes from silky to wallpaper paste in seconds.
- Chilled and thinned with cream this is vichyssoise, which wants noticeably more salt cold than hot.