Creamy Potato Leek Soup
Potato leek soup gets its body from potatoes simmered until fork-tender, then puréed with softened leeks and broth. A little cream stirred in at the end makes this version richer without needing flour. Rinse the leeks between their layers to keep grit out of the soup, and stop blending as soon as it is smooth so the potatoes do not turn gummy. Finish each bowl with green onion, fresh thyme, and cracked black pepper.
Prep time: 15 minutes | Cook time: 30 minutes | Total time: 45 minutes | Serves: 4
Ingredients for Creamy Potato Leek Soup
- 2 tablespoons unsalted butter (30g)
- 2 large leeks, white and light green parts only (about 350g trimmed)
- 3/4 teaspoon kosher salt, plus more to taste
- 2 garlic cloves, minced
- 1 1/2 pounds Yukon Gold potatoes, peeled and cut into 1/2-inch cubes (680g)
- 4 cups low-sodium chicken broth or vegetable broth (960ml)
- 3 fresh thyme sprigs for simmering, plus 2 to 4 small sprigs for garnish
- 1/4 teaspoon freshly ground black pepper, plus more for garnish
- 1/2 cup heavy cream (120ml)
- 2 tablespoons thinly sliced green onion
- Up to 1/2 cup warm broth or water, if needed to thin the soup
How to Clean Leeks
Trim off the roots and tough dark green tops. Split the white and light green portions lengthwise, fan the layers apart, and rinse thoroughly under running water. Check between the layers for grit, then slice the leeks and drain them before cooking.
How to Make Creamy Potato Leek Soup
- Prepare the vegetables: Clean and slice the leeks as described above. Peel the potatoes and cut them into even 1/2-inch cubes so they cook at a similar rate.
- Soften the leeks: Warm a 5- to 6-quart soup pot or Dutch oven over medium heat, then add the butter and reduce the heat to medium-low. Add the leeks and salt. Cook, stirring occasionally, for 6 to 8 minutes, until soft and translucent but not browned. Add the garlic and cook for about 30 seconds, until fragrant.
- Simmer the potatoes: Stir in the potatoes, 4 cups broth, and 3 thyme sprigs. Bring to a gentle simmer over medium heat, then lower the heat and partially cover the pot. Stir as the soup returns to a simmer. Start checking the potatoes after about 12 minutes; they will typically need 12 to 18 minutes, but size and stove heat can change the timing. Cook until a fork passes easily through a potato cube.
- Blend until smooth: Remove the simmered thyme sprigs and turn off the heat. Purée the soup with an immersion blender until no potato pieces remain, then stop. Prolonged blending can make the potatoes gummy. If the soup is too thin, simmer it gently, uncovered, for a few minutes before adding the cream.
- Add the cream: Stir in the cream and warm over low heat for 2 to 3 minutes without boiling. Add the 1/4 teaspoon black pepper, then taste and adjust the salt. If the soup is too thick, stir in warm broth or water a little at a time until it is spoonable.
- Garnish and serve: Ladle the smooth soup into shallow bowls. Gather the sliced green onion loosely on one side, place fresh thyme sprigs on the other, and scatter a little cracked black pepper over the surface.
If using a countertop blender instead, follow its instructions for hot liquids. Blend in small batches with the jar no more than halfway full; hot soup can build pressure in an overfilled blender and splatter.
Adjusting the Texture
The potatoes should be very tender before blending; firm pieces will not purée smoothly. The soup may also thicken as it stands. Add warm broth gradually when reheating until it reaches the consistency you want.
For a dairy-free version, use 2 tablespoons olive oil in place of the butter and omit the cream or use a plant-based cream alternative. The finished soup will differ in richness. Russet potatoes can replace Yukon Golds, though they may make a starchier purée; blend only until smooth.
Serving, Storage, and Freezing
Serve hot with crusty bread or toasted baguette, or alongside a simple salad or sandwich. Add the green onion and fresh thyme just before serving.
Cool leftovers promptly and refrigerate in an airtight container for 3 to 4 days. Reheat gently on the stovetop, stirring occasionally, and add a splash of broth if the soup has thickened.
If you plan to freeze the soup, freeze it before adding the cream for the best chance of maintaining its texture. Thaw in the refrigerator, reheat gently, and stir in the cream near the end. A finished batch containing cream may change texture after freezing.
For another smooth vegetable soup, try Creamy Roasted Cauliflower Soup. For a heartier option with beans and mushrooms, see High-Protein White Bean Soup with Mushrooms.
Nutrition
Approximate nutrition per serving, based on 4 servings: 350 calories, 7g protein, 17g fat, and 43g carbohydrates. Approximate nutrition per 100g: 65 calories, 1g protein, 3g fat, and 8g carbohydrates. Values vary with the broth and ingredient brands used.
Equipment
- 5- to 6-quart soup pot or Dutch oven
- Immersion blender
- Knife and cutting board
Ingredients
- 2 tablespoons unsalted butter (30 g)
- 2 large leeks, white and light green parts only (about 350 g trimmed)
- 3/4 teaspoon kosher salt, plus more to taste
- 2 garlic cloves, minced
- 1 1/2 pounds Yukon Gold potatoes, peeled and cut into 1/2-inch cubes (680 g)
- 4 cups low-sodium chicken broth or vegetable broth (960 ml), plus up to 1/2 cup warm broth or water if needed
- 3 fresh thyme sprigs for simmering, plus 2 to 4 small sprigs for garnish
- 1/4 teaspoon freshly ground black pepper, plus more for garnish
- 1/2 cup heavy cream (120 ml)
- 2 tablespoons thinly sliced green onion
Instructions
- Trim the roots and tough dark green tops from the leeks. Split the white and light green parts lengthwise, fan apart the layers, and rinse thoroughly between them. Slice and drain the leeks.
- Peel the potatoes and cut them into even 1/2-inch cubes.
- Warm a 5- to 6-quart soup pot over medium heat. Add the butter and reduce the heat to medium-low. Add the leeks and salt; cook, stirring occasionally, for 6 to 8 minutes until soft and translucent but not browned.
- Add the garlic and cook for about 30 seconds, until fragrant.
- Stir in the potatoes, 4 cups broth, and 3 thyme sprigs. Bring to a gentle simmer over medium heat, then lower the heat and partially cover the pot. Cook for 12 to 18 minutes, stirring as the soup returns to a simmer, until a fork passes easily through a potato cube.
- Remove the thyme sprigs and turn off the heat. Purée with an immersion blender just until smooth.
- If the soup is too thin, simmer it gently uncovered for a few minutes. Stir in the cream and warm over low heat for 2 to 3 minutes without boiling.
- Stir in the 1/4 teaspoon black pepper. Taste and adjust the salt. If the soup is too thick, add warm broth or water a little at a time.
- Ladle into bowls and garnish with green onion, fresh thyme sprigs, and cracked black pepper.
Tips
- Rinse between the leek layers to remove hidden grit.
- Cut the potatoes into even cubes so they cook at a similar rate.
- Blend only until smooth; prolonged blending can make the potatoes gummy.
- Check the potatoes for tenderness before blending.
- Add warm broth gradually if the soup thickens as it stands.
Variations
- Dairy-Free Potato Leek Soup: Use 2 tablespoons olive oil instead of butter and omit the cream or use a plant-based cream alternative.
- Russet Potato Leek Soup: Replace the Yukon Gold potatoes with russet potatoes; blend only until smooth, as russets may make the soup starchier.