Potato leek soup
Creamy potato leek soup made with half-and-half rather than heavy cream. Yukon Golds give it body and slowly sweated leeks give it sweetness, so it needs less dairy.
- 235
- kcal
- 6g
- protein
- 7g
- fat
- 39g
- carbs
- Prep
- 15 min
- Cook
- 40 min
- Serves
- 6
Photograph by kaboompics on Pixabay
Ingredients
- 3 large leeks, white and light green parts only
- 2 tbsp unsalted butter
- 2 cloves garlic, sliced
- 2 lb Yukon Gold potatoes, peeled and cut in 1-inch chunks
- 5 cups low-sodium chicken or vegetable broth
- 2 sprigs fresh thyme and 1 bay leaf
- 1/2 cup half-and-half
- 1 tsp kosher salt, plus more to taste
- White or black pepper
- Chopped chives, to serve
Method
-
1
Clean the leeks
Halve the leeks lengthwise and slice them thinly. Swish them in a big bowl of cold water, leave a minute for the grit to sink, and lift them out with your hands.
-
2
Sweat the leeks
Melt the butter in a large pot over medium-low heat. Add the leeks and salt, cover, and cook 10 to 12 minutes, stirring now and then, until very soft but not browned. Add the garlic for the last minute.
-
3
Simmer the potatoes
Add the potatoes, broth, thyme and bay leaf. Bring to a boil and simmer 15 to 20 minutes, until the potatoes break when pressed with a spoon.
-
4
Blend
Remove the herbs and blend until smooth with a stick blender. Do not run it longer than you need to: overworked potato turns gluey.
-
5
Finish
Stir in the half-and-half, warm through, and season with salt and pepper. Serve with chives.
Why Yukon Golds
Yukon Gold potatoes are medium-starch. They blend into a smooth, buttery soup. Russets work, but being higher in starch they go gluey faster. Waxy red potatoes tend to turn gluey when blended. If you only have russets, use them and blend them a little less.
Don't overblend
Potato soup turns from creamy to gluey when it is blended too long. The blades burst the potato's cells and release their gelatinized starch into the liquid. A stick blender for 30 to 60 seconds is right. A countertop blender on high works faster and is easier to overdo, so pulse it and stop as soon as the soup is smooth. If you like some texture, blend half and stir it back into the rest.
Sweat the leeks, don't brown them
The covered pot and low heat in step two let the leeks cook in their own steam until they are soft and sweet. Browned leeks taste good, but they turn the soup beige and a little bitter. Leeks have a mild, sweet onion flavor that you only get by cooking them gently.
Leeks hold grit between their layers, which is why you slice them before washing them. Once sliced, the layers separate in the water and the dirt sinks. Lift the leeks out instead of pouring them into a strainer, or the grit goes right back on top.
Lighter or richer
Half a cup of half-and-half across six bowls is enough to make the soup taste creamy, because the potatoes do most of the work. Here is how the options compare:
- Lighter: whole milk instead of half-and-half saves about 15 kcal a bowl. Or leave out the dairy entirely: the potatoes alone make a perfectly creamy soup.
- Richer: heavy cream instead of half-and-half adds about 40 kcal a bowl.
- Vegan: use olive oil for the butter, vegetable broth, and a splash of unsweetened oat milk at the end.
Instant Pot
Sweat the leeks on Sauté, add the potatoes, broth and herbs, and cook 6 minutes at high pressure with a 10-minute natural release. Then blend and finish as above.
Serve it cold: vichyssoise
Chilled potato leek soup is vichyssoise, a classic summer soup. Blend it very smooth, chill it overnight, and thin it with a little cold broth or milk, because it thickens a lot in the fridge. Cold food needs more seasoning than hot, so taste it again and add more salt after chilling.
Keeping it
Four days in the fridge. Potato soups freeze less well than most soups, because the potato turns slightly grainy on thawing. It is still good, especially if you blend it again briefly after reheating.
What it is worth nutritionally
About 235 kcal a bowl, with 6 g of protein and 7 g of fat. That is well below a restaurant-style potato soup made with heavy cream. Potatoes are better nutritionally than their reputation suggests. A medium potato has more potassium than a banana, along with vitamin C and B6. Leeks bring a type of fiber called inulin, which feeds beneficial gut bacteria. The same fructans can bother people with IBS, since leeks are high in FODMAPs. To make the soup a full meal, serve it with a salad with chicken or eggs, or blend a can of white beans into the pot.
