Irish Soup Recipe: Potato and Leek

This Irish-style potato and leek soup is a smooth, warming bowl made with potatoes, leeks, onion, stock, and a little cream. It is simple enough for a weeknight, and its mild, savory flavor works equally well as a light lunch or the start of a larger meal.

Ingredients

3 large leeks, about 1 lb (450 g) trimmed weight
1 medium yellow onion, about 5 oz (150 g), peeled and chopped
3 tablespoons (42 g) unsalted butter
1 tablespoon (15 ml) olive oil
2 lb (900 g) floury potatoes, such as russets or Maris Piper, peeled and cut into 1-inch (2.5 cm) pieces
6 cups (1.4 L) low-sodium vegetable or chicken stock
1 bay leaf
1 teaspoon (1 g) fresh thyme leaves, or ½ teaspoon (0.5 g) dried thyme
1 teaspoon (6 g) fine salt, plus more to taste
½ teaspoon (1 g) freshly ground black pepper, plus more to taste
½ cup (120 ml) heavy cream
2 tablespoons (6 g) finely snipped fresh chives, for serving

Instructions

Clean and cut the leeks. Trim off the root ends and dark green tops, leaving the white and pale green sections. Slice the leeks lengthwise, then cut them crosswise into thin half-moons. Separate the layers and rinse them thoroughly in a bowl of cold water, swishing to release any grit. Lift the leeks out rather than pouring the water over them, and drain well. Sand can hide between the layers, so rinse a second time if the water looks dirty.
Prepare the vegetables. Chop the onion and peel the potatoes. Cut the potatoes into similarly sized pieces so they soften at about the same rate. Keep them in a bowl of cold water if you need a few minutes before cooking, then drain and pat them dry. Cutting the potatoes before heating the pot keeps the cooking stage moving smoothly.
Soften the leeks and onion. Set a large, heavy pot or Dutch oven over medium-low heat. Add the butter and olive oil. Once the butter has melted, stir in the leeks and onion with a pinch of the measured salt. Cook for 8 to 10 minutes, stirring every minute or two, until the vegetables look soft and glossy but have not browned. Lower the heat if the edges start to take on color; gentle cooking keeps the soup sweet and mild.
Add potatoes, stock, and herbs. Stir in the drained potatoes, stock, bay leaf, thyme, remaining salt, and pepper. Bring the liquid just to a gentle boil, then reduce the heat so it simmers steadily. Cover the pot with the lid slightly ajar and cook for 20 minutes, stirring once or twice. The potatoes are ready when a knife slips easily into the center of a larger piece.
Remove the bay leaf and blend. Take the pot off the heat and fish out the bay leaf. For a fully smooth soup, use an immersion blender directly in the pot, keeping the blender head submerged to avoid splashes. Blend in short bursts until no potato pieces remain. Alternatively, blend in batches in a countertop blender, filling it no more than halfway and venting the lid according to the appliance instructions so hot steam can escape.
Finish with cream and adjust. Stir in the cream and return the pot to low heat for about 3 to 5 minutes, just until the soup is hot. Do not let it boil vigorously after adding the cream. Taste and add more salt or pepper if needed. If the soup seems thicker than you like, stir in warm stock or water a little at a time; if it is thinner, let it simmer gently for a few minutes before adding the cream.
Serve. Ladle into warm bowls and scatter chives over each portion. A small swirl of cream or a few grinds of black pepper can be added at the table. Serve while hot, with bread or another accompaniment if desired.

Tips

Wash leeks patiently. Leeks often trap soil between their layers, and grit can spoil the smooth texture. Slicing them before rinsing makes it easier to separate the layers and wash away debris. Lift the slices from the water so the grit stays at the bottom of the bowl.
Choose a potato that breaks down. Floury potatoes such as russets give the soup body and blend smoothly. Waxy potatoes can work, but they may leave a slightly less silky result. If using waxy potatoes, blend only until smooth and avoid prolonged blending, which can make potatoes gluey.
Keep the vegetables pale. Browning the leeks and onion gives the soup a deeper, sweeter flavor, but the classic mild style depends on softening them without browning. Use medium-low heat and stir regularly. If the pot gets too hot, add a tablespoon or two of stock to cool it down.
Adjust texture gradually. The soup thickens as it cools, especially when made with russet potatoes. Add warm stock or water in small splashes until it reaches the consistency you want. Season after thinning, because extra liquid can soften the salt and pepper flavor.

Serving Suggestions

Serve the soup in warmed bowls with brown soda bread, crusty bread, or buttered toast for dipping. A simple green salad with a sharp vinaigrette makes a fresh contrast to the creamy, soft texture; sliced apples or a few pickles can also bring a bright, crisp note to the plate. For a more substantial meal, pair it with an open-faced cheese sandwich or a small serving of roasted vegetables.

Chives give each bowl a clean onion flavor, while chopped parsley is a good alternative if that is what you have. You can finish with a little cracked black pepper, a teaspoon of cream, or a few crisp croutons. Add toppings just before serving so herbs stay fresh and crunchy additions do not soften in the soup.

Variations

Make it dairy-free: Replace the butter with another tablespoon of olive oil and omit the cream. The blended potatoes still make a satisfying, creamy-textured soup. For a richer finish, stir in ½ cup (120 ml) unsweetened oat cream or a splash of coconut milk; coconut milk adds a noticeable flavor, so use it only if that suits your meal.

Leave it a little rustic: Instead of blending the whole pot, mash some of the potatoes with a potato masher and leave the rest in small pieces. This gives the soup a thicker, more homestyle texture. You can also blend only half the soup and stir it back into the pot.

Add greens or herbs: Stir in 2 cups (60 g) baby spinach during the final few minutes, allowing it to wilt before serving. For a brighter herbal note, use a small handful of parsley in place of some of the chives. Add delicate greens near the end rather than simmering them for the full cooking time.

Use different stock: Vegetable stock keeps the dish meat-free, while chicken stock gives it a fuller savory flavor. Choose a low-sodium stock so you can season the finished soup to taste. If you only have regular salted stock, begin with half the listed salt and adjust after blending.

Storage and Reheating

Cool leftovers promptly and refrigerate them within 2 hours of cooking in a covered container. The soup keeps for 3 to 4 days in the refrigerator. It thickens as it chills, so loosen it with a splash of stock, milk, or water when reheating. Warm it in a saucepan over medium-low heat, stirring often, or microwave individual portions in a covered, microwave-safe bowl, pausing to stir. Reheat leftovers to 165°F (74°C), as recommended by USDA FSIS, and avoid repeatedly cooling and reheating the same pot.

You can freeze the soup for up to 2 months for best quality, although potato-based soups can become slightly grainy after thawing. For a smoother result, freeze it before adding the cream, then thaw it overnight in the refrigerator, reheat it, and stir in the cream at the end. If it has already been made with cream, freezing is still possible, but whisk or blend it briefly after reheating if the texture separates. Freeze in meal-size portions and leave a little room in each container for expansion.

Frequently Asked Questions

Is this a traditional Irish soup?
Potato and leek soup is a familiar style of home soup in Ireland and elsewhere, but recipes vary by household and region. Some versions are made with milk, some with cream, and others rely on potatoes for a thick texture without dairy. This recipe is an Irish-style version, not a claim that there is only one traditional method.

Can I make it without a blender?
Yes. Use a potato masher to crush the cooked potatoes in the pot, leaving some pieces intact for a rustic finish. The soup will be less silky, but it will still be thick and comforting. A handheld potato ricer can make it smoother, though it takes more effort than blending.

Why did my soup turn gluey?
Potatoes release starch when they are overworked, particularly floury varieties. Blend only until smooth, and avoid running a countertop blender for longer than needed. If the soup is already gluey, gently stir in warm stock to loosen it; further blending is unlikely to improve the texture.

Can I make it ahead?
Yes. Make the soup up to 3 days ahead and refrigerate it in a covered container. For the best texture, you can leave out the cream until reheating, then stir it in once the soup is hot. The flavor often tastes more rounded after a day, though the chilled soup will be thicker.

Can I use milk instead of heavy cream?
Yes. Use ½ cup (120 ml) whole milk for a lighter finish, or use half-and-half for a middle ground. Milk makes the soup less rich, and it can scorch more easily, so keep the heat low after adding it and do not bring the pot to a hard boil.

What if I do not have leeks?
Use 2 medium yellow onions, about 10 oz (300 g) total, in place of the leeks. The soup will taste more like a potato and onion soup and will lose the gentle, lightly sweet leek flavor, but the method and cooking time remain much the same.

More recipes to cook

Safety notes: safe minimum internal temperatures from USDA FSIS; raw and undercooked fish guidance from the U.S. FDA. Food safety notes

Spotted an error? Tell us and we will correct it (corrections policy).