Cawl Cennin (Welsh Leek and Potato Soup)
A simple, chunky soup of leeks, potatoes and stock: humble Welsh cooking built around the national emblem.
AI assistance: the introduction, ingredient list, method, tips and FAQ on this page were drafted with an AI writing tool, working from long-established traditional methods. Named editor who reviewed it: owner to supply How we work
- Prep
- 15 min
- Cook
- 35 min
- Total
- 50 min
- Makes
- 4 servings
- Difficulty
- Easy
- Course
- Soup
- Cuisine
- Welsh
Cawl cennin simply means leek soup in Welsh. The leek is a national emblem of Wales, worn on St David's Day, and this soup is a cheap, comforting way to make the most of it.
Traditionally it is left chunky rather than blended, with a little cream or milk stirred in at the end.
Ingredients
- 25 g butter
- 3 leeks, about 600 g, trimmed, washed and sliced
- 1 onion, chopped
- 500 g floury potatoes, peeled and diced
- 1.2 litres chicken or vegetable stock
- 100 ml single cream or whole milk, optional
- salt and ground black pepper
- chopped parsley or chives, to serve
Equipment
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Method
- 1
Melt the butter in a large saucepan. Add the leeks and onion, cover and cook gently for 10 minutes, stirring now and then, until soft but not coloured.
- 2
Add the potatoes and stock, bring to the boil, then simmer for 20 minutes until the potatoes are tender.
- 3
Crush some of the potatoes against the side of the pan to thicken the soup slightly, or blend half of it if you prefer it smoother.
- 4
Stir in the cream, season well and serve scattered with parsley or chives, with bread and Welsh cheese.
Tips
Wash leeks after slicing: swish the rings in a bowl of cold water so the grit sinks.
For a heartier Welsh pot with lamb, see our cawl. Scotland's chicken and leek soup is cock-a-leekie.
If it goes wrong
| Problem | Likely cause | Fix |
|---|---|---|
| Gritty soup | Soil trapped between the leek layers | Slice, then wash the leeks in plenty of water |
| Too thin | Not enough potato broken down | Crush more potatoes or simmer uncovered for 10 minutes |
Frequently asked questions
Can I freeze leek and potato soup?
Yes, before adding the cream. Cool, freeze for up to 3 months, and stir in the cream when reheating.
Should I use the green part of the leek?
Use the white and pale green parts. The dark green tops are tough, but they are good in stock.
Is cawl cennin vegetarian?
It is if you use vegetable stock.
Guides for this recipe
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Card photos: A chef's knife with a wooden handle, Frank Schulenburg via Wikimedia Commons, CC BY-SA 4.0, cropped; Kitchen knives held on a wall-mounted magnetic strip, Phil! Gold from Pikesville, MD, USA via Wikimedia Commons, CC BY-SA 2.0, cropped; Copper pans and a kettle on an old kitchen range, Silar via Wikimedia Commons, CC BY-SA 4.0, cropped; A small stainless steel saucepan with a lid, Cooks & Kitchens from Darlington, UK via Wikimedia Commons, CC BY 2.0, cropped; A loaf of bara brith on a festive table, James Petts from London, England via Wikimedia Commons, CC BY-SA 2.0, cropped; A bowl of meaty Welsh cawl with bread, Worm That Turned via Wikimedia Commons, CC BY-SA 4.0, cropped; A buttered stack of crempog, Welsh pancakes, FruitMonkey via Wikimedia Commons, CC BY-SA 4.0, cropped. All credits: image credits.