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Potato Leek Soup Recipe

This rich Potato Leek Soup recipe marries the flavor of leeks sautéed in butter with garlic, thyme, and potatoes. It's creamy without cream, cozy and warming, easy to make, and can be made gluten free!
Course Soup
Cuisine American
Prep Time 10 minutes
Cook Time 20 minutes
Servings 6 servings
Calories 236kcal

Ingredients

  • 1 tablespoon light olive oil or avocado oil
  • 2 tablespoons unsalted butter
  • 3 medium to large leeks white and light green parts only, thinly sliced and rinsed well
  • 3 large cloves garlic minced
  • 2 teaspoons minced fresh thyme leaves plus more for garnish if desired
  • 2 cups vegetable stock or chicken stock for richer flavor
  • 1 bay leaf
  • 1 teaspoon salt
  • 1/4 teaspoon black pepper
  • 1 pound starchy potatoes peeled and cubed into about 3/4-inch pieces (such as Russet; 1 pound is about 3 medium-large potatoes)
  • 3 tablespoons all-purpose flour
  • 3 cups milk whole for richest flavor, but low-fat will work

Instructions

  • Add the oil and butter to a 5-quart pot over medium heat. When the butter is melted, add the leeks and cook until softened and just starting to brown, about 5 to 7 minutes, stirring occasionally.
  • Add the garlic and thyme and cook until fragrant, about 30 seconds to 1 minute, stirring constantly.
  • Add the vegetable stock, bay leaf, salt, black pepper, cubed potato and bring to a boil. Turn the heat down so the soup simmers, and cook until the potatoes are tender, about 6 to 8 minutes.
  • Whisk together the flour and milk in a medium bowl. Add this mixture to the soup and turn the heat up so it comes up to a gentle boil, stirring frequently. Once boiling, cook 1 minute, stirring constantly, then turn off the heat.
  • Use a potato masher or fork to mash a few of the potatoes in the soup to make it creamy; give it a stir.
  • Taste and season with additional salt and pepper as desired; serve.

Notes

  • Leeks Substitute: If you don’t have leeks or can’t eat leeks, you can make this recipe with 2 medium onions instead.
  • To Make it Completely Smooth: For a completely smooth soup without any pieces of potato, puree the soup using a blender, food processor, or immersion blender.
  • Herb Garnish Options: Instead of using fresh thyme as a garnish, you can use fresh parsley or fresh chives.
  • Gluten Free Version: To make this soup gluten free, omit the flour and use 1 1/2 tablespoons of cornstarch instead. Alternatively, you can omit the flour and mash about half of the potatoes to thicken this soup.
  • How to Tell When the Potatoes Are Done: The potatoes are done cooking when you insert a paring knife in one and it slides right out.
  • Chicken Stock Tip: To make this soup as rich and flavorful as possible, use chicken stock (instead of vegetable stock) and whole milk (instead of reduced fat milk).
  • For Even More Depth of Flavor: For even more depth of flavor, before you cook the leeks, crisp 2 slices of beef bacon in the pot. Remove and crumble it to sprinkle on top before serving. Make the soup in the same pot, and omit the oil.

How to Make This Soup in the Instant Pot

  1. Heat the oil and butter in an Instant Pot on the "Saute" function. Once hot, add the leek and cook until it's starting to soften, about 5 to 7 minutes, stirring occasionally. Stir in the garlic and thyme, and cook 1 minute more, stirring constantly. Press "Cancel" to turn off the "Saute" function. 
  2. Stir in the vegetable stock, bay leaf, salt, black pepper, and cubed potato. Cover the Instant Pot and set it to "Manual, High Pressure" for 1 minute. Once it's done, vent it to release the steam.
  3. Whisk together the flour and milk in a medium bowl. Add this mixture to the soup in the Instant Pot. Turn on the "Saute" function so it comes up to a boil, stirring frequently. Once boiling, cook 1 minute, stirring constantly, then press "Cancel".
  4. Use a potato masher or fork to mash a few of the potatoes in the soup to make it creamy; give it a stir.
  5. Taste and season with additional salt and pepper as desired; serve.

Nutrition

Calories: 236kcal | Carbohydrates: 30g | Protein: 7g | Fat: 10g | Saturated Fat: 5g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 4g | Trans Fat: 1g | Cholesterol: 22mg | Sodium: 767mg | Potassium: 573mg | Fiber: 2g | Sugar: 9g | Vitamin A: 1257IU | Vitamin C: 11mg | Calcium: 182mg | Iron: 2mg