Cullen Skink: Easy Scottish Fish Soup Recipe

Cullen skink is a traditional Scottish soup that contains smoked haddock, potatoes, leek, and milk or cream. There are many variations of this dish, and each Scottish family has its own recipe that they pass down through the generations.

It is a dish that makes the most of some of Scotland’s finest ingredients, although the ingredients are readily available in most other locations. Cullen skink is a hearty and substantial Scottish soup that is filling. You may also find it warming on a cold day.

Vaiations of Cullen Skink

In many Scottish households, they use leftover mashed potato as a thickener for the soup. However, other people have diced potato in this Scottish soup. I prefer to use a little cornflour as a thickener and to have pieces of potato to add substance.

Some recipes have leeks while others have onion. My preference is the milder flavour of leeks, but you can interchange the leeks in this recipe for onions if you wish.

Our recipe for this easy soup with fish involves poaching the smoked haddock in the milk and sautéing the leeks in the butter before making a rue with the butter, milk, and cornflour. Using this method allows you to get as much flavour from the fish and leeks into the soup as possible.

More flavour is added with salt, white pepper, and parsley. Although most of the soup recipes on Super Souper Ed list black pepper as a seasoning, white pepper is a better option with fish, and it means the soup is not discoloured. Parsley is a herb that works well with fish dishes, although you can omit the parsley if you do not like this flavour.

Ideally, ask the fishmonger to remove any bones and the skin, as you do not want bones or skin in your fish soup. However, you can do this yourself at home. It is often easier to remove the skin after cooking the fish. If you are a fan of fish skin, you can leave it on if you prefer.

If you enjoy this recipe, then you may like our other Scottish soups, Scotch broth and cock-a-leekie soup.

Here is how to make the perfect Cullen skink.

Ingredients for Cullen Skink

• 300g smoked haddock
• 300g potatoes, peeled and diced
• 1 large leek, finely sliced
• 500 ml full-fat milk
• 250 ml fish, chicken, or vegetable stock
• 150 ml double cream
• 1 tbsp cornflour (or plain flour)
• 3 oz butter
• 1 tbsp olive oil
• 1 tsp dried parsley
• Salt and white pepper to taste
• Chopped chives to decorate (optional)

How to Make Cullen Skink

1. Remove the skin and bones from the smoked haddock if they are not skinless and boneless fillets.
2. Quarter the leek lengthways, then finely slice.
3. Peel and dice the potatoes into 1 cm cubes.
4. Put the milk into a saucepan over medium heat to bring to a simmer.
5. Turn down the heat and add the haddock to poach in the milk for 5 minutes before removing and setting aside in a large bowl. Keep an eye on the pan as milk can easily boil over.
6. Meanwhile, add two ounces of the butter to a large pan with the oil. Melt the butter over medium heat on the hob.
7. Add the leeks and potatoes and cook for 10 minutes until both are softened.
8. Spoon out the leek and potatoes, then set them aside in the large bowl with the haddock.
9. Add another ounce of butter to the saucepan and melt.
10. Turn down the heat of the hob to low, then sprinkle over the cornflour or plain flour.
11. Stir the butter and flour together to make a paste.
12. Add a splash of the milk you used to poach the haddock and stir into the butter and flour paste to create a rue.
13. Continue this process, adding a little of the milk at a time, and continue stirring to prevent lumps.
14. When you have added all the milk, turn the hob back to medium, then return the smoked haddock, leeks, and potatoes to the pan.
15. At the same time, add the double cream and stock to the pan.
16. Season the Cullen skink with salt and white pepper and add the parsley/
17. Cook for a further 10 minutes.
18. Serve the Cullen skink into bowls, and sprinkle with chopped chives.

Additional Tips

• Traditional Cullen skink uses smoked haddock, but you can use an alternative smoked fish or use unsmoked haddock if you do not like the smoked flavour.
• Switch the leek for a large, finely chopped onion if you prefer.
• Reduce the calories in this soup with fish by omitting the double cream.
• If you are on a gluten-free diet, do not make a rue for the dish. Instead, add a couple of spoons of mashed potato to the liquids, as the starch from the potatoes will thicken the soup.