Five-Ingredient Potato Leek Soup
This five ingredient soup is simple, fairly quick, and oh-so-good. It calls for a good amount of butter and cream. Use it. It is worth it, even if it means having a smaller serving size. I usually serve this soup for dinner with a small panini or hearty salad on the side, but it also works amazingly well as a holiday appetizer. Simply place the prepared soup in a slow cooker on warm or low, set a ladle and some small bowls or mugs nearby, and guests can serve themselves as you’re putting the finishing touches on the main course.
- Servings 10-12 (1 cup) servings
- 113 grams (4 ounces) butter
- 4 large leeks, sliced* (about 1.3 liters/5 1/2 cups after slicing)
- 2 large russet potatoes, peeled and diced into 1.3 cm (1/2-inch) pieces**
- 1.2 liters (5 cups) unsalted vegetable stock, canned or home made
- 118 ml (1/2 cup) heavy cream
- Kosher salt
- Fresh ground pepper
- Fresh chives, finely chopped (optional, for garnish)
*About 680 grams (1 1/2 pounds) unpeeled potatoes
**Katie notes: For cleaning leeks, I recommend the use of a salad spinner. First slice off and discard the root and dark green top. Slice the remaining white and light green section in half lengthwise and cut them crosswise into 1.3 cm (1/2-inch) slices. Fill the bowl of a salad spinner with cold water. Add the leeks to the colander portion, dunk into the water, and break apart the slices to release the dirt and grit. Lift the colander out of the water. Dump the dirty water (or use to water plants) and refill with fresh, cold water. Repeat until the leeks are free of any grit. Place the colander into the empty salad spinner bowl and spin to dry. Use in a recipe or store in a zip-top bag for future use. To freeze the cleaned, sliced leeks, lay them out on a parchment-lined baking sheet in a single layer and freeze. Once frozen, combine in a zip-top bag and store in the freezer for up to a few months.
1. Melt 57 grams (2 ounces) of the butter in a heavy Dutch oven over medium heat, until it starts to lightly bubble. Add the leeks and stir to coat with butter. Season with about 2.5 ml (1/2 teaspoon) salt. Cover and cook until the leeks are tender, about 10 minutes. Stir frequently.
2. When the leeks are tender, add the potato and stir to combine. Season again with a 1.2 to 2.5 (1/4 to 1/2 teaspoon) salt. Cover and cook, stirring occasionally, until the potatoes begin to soften (but not brown), about 10 minutes. The leeks should be very tender and almost falling apart.
3. Add the stock and bring to a boil. Reduce the heat to medium-low and simmer and uncovered until the vegetables are very tender, about 30 minutes. Remove the pot from heat.
4. Using an immersion blender, puree the soup until smooth — or, if using a standard blender, allow to cool until no longer steaming, and puree in batches then return to the pot. Cut the remaining butter into pieces and add to the soup. Stir until melted. Add the cream and stir to combine. Season with salt and pepper to taste. If you’re not serving right away, you can keep the soup warm over very low heat, stirring frequently until ready to serve. Ladle into bowls and garnish with fresh chives.
Katie says —
Make ahead: The soup can be made up to 2 days in advance. Stash it in the fridge after adding the butter, cream, and adjusting seasoning. Reheat in a dutch oven over medium-low heat, stirring frequently.
Really make ahead: If you’d like to make it ahead beyond a few days in advance, puree the soup and then freeze before adding the butter and cream. To heat and finish, thaw the soup in the fridge overnight and transfer to a heavy pot. Bring to a simmer over medium-high heat. Reduce the heat to low and add the butter and cream as instructed above. Season with salt and pepper, to taste.
Dutch oven with lid
Immersion blender (recommended) or blender