Potato and Leek Soup embodies the soul of French country cooking, transforming humble ingredients into a velvety, sophisticated dish that has warmed kitchens and hearts for centuries. This classic soup, known in France as Potage Parmentier, showcases how the gentle sweetness of leeks pairs beautifully with the earthy comfort of potatoes, creating a harmonious blend that’s both rustic and refined. The magic lies in the slow, careful cooking that allows the leeks to release their subtle onion-like flavor while the potatoes break down to create natural creaminess without heavy cream. Whether served chunky for a hearty family meal or pureed smooth for an elegant dinner party starter, this soup delivers that perfect balance of simplicity and sophistication that defines the best of French cuisine. The addition of fresh herbs and a swirl of cream elevates it from peasant food to restaurant-quality elegance, while maintaining that comforting, homestyle appeal that makes it a timeless favorite across cultures and seasons.
Serving Quantity
This recipe serves 6-8 people as a starter or 4-5 people as a main course with crusty bread.
Ingredients
- 3 large leeks, white and light green parts only
- 2 pounds Yukon Gold potatoes, peeled and cubed
- 4 tablespoons butter
- 1 medium onion, diced
- 2 cloves garlic, minced
- 6 cups chicken or vegetable broth
- 1 bay leaf
- 1 sprig fresh thyme
- 1/2 cup heavy cream
- 2 tablespoons fresh chives, chopped
- 1 tablespoon fresh parsley, chopped
- 1 teaspoon salt
- 1/2 teaspoon white pepper
- 1/4 teaspoon nutmeg
- 2 tablespoons olive oil
- Croutons for garnish (optional)
Preparing the Leeks
Leeks require careful cleaning as dirt and sand often hide between their layers. Trim off the dark green tops and root ends, keeping only the white and pale green portions. Cut the leeks in half lengthwise, then slice them into half-moons about 1/2 inch thick.
Place the sliced leeks in a large bowl of cold water and swish them around vigorously to release any trapped dirt. Let them sit for a few minutes, allowing the dirt to settle to the bottom, then lift the leeks out with your hands rather than draining, which could redistribute the dirt.
Rinse the cleaned leeks once more under cold running water to ensure they’re completely clean. Pat them dry with paper towels or a clean kitchen towel before cooking.
Preparing the Potatoes
Peel the potatoes and cut them into uniform cubes, roughly 1-inch in size. Uniform pieces ensure even cooking and consistent texture in the finished soup. Yukon Gold potatoes work best for this soup because they have the perfect balance of starch and wax content.
Place the cubed potatoes in a bowl of cold water to prevent browning while you prepare the other ingredients. This also removes some surface starch, which helps create a cleaner-tasting soup.
Building the Flavor Base
In a large, heavy-bottomed pot or Dutch oven, melt the butter over medium heat. Add the cleaned leeks and diced onion, stirring to coat with the butter. The butter should sizzle gently but not brown.
Cook the leeks and onion slowly for 8-10 minutes, stirring occasionally, until they’re very soft and translucent but not browned. This slow cooking process, called sweating, allows the vegetables to release their natural sugars and develop deep, sweet flavors.
Add the minced garlic and cook for another minute until fragrant. Be careful not to let the garlic brown, as it can become bitter and overpower the delicate leek flavor.
Adding the Potatoes and Liquid
Drain the potatoes and add them to the pot with the softened leeks. Stir everything together and cook for 2-3 minutes, allowing the potatoes to absorb some of the aromatic flavors from the leeks and butter.
Pour in the broth, making sure it covers the vegetables by about 1 inch. Add the bay leaf and fresh thyme sprig. The herbs will infuse the soup with subtle aromatic notes as it simmers.
Bring the mixture to a gentle boil, then reduce the heat to maintain a steady simmer. Partially cover the pot and cook for 20-25 minutes until the potatoes are completely tender and easily pierced with a fork.
Choosing Your Texture
At this point, you can decide whether you want a chunky, rustic soup or a smooth, elegant puree. For a chunky texture, simply mash some of the potatoes with a potato masher right in the pot, leaving plenty of pieces for texture.
For a smooth soup, remove the bay leaf and thyme sprig, then use an immersion blender to puree the soup to your desired consistency. Alternatively, you can transfer portions to a regular blender, but be careful with hot liquids and work in batches.
For the silkiest texture, you can pass the pureed soup through a fine mesh sieve, pressing the solids through with the back of a ladle. This creates an incredibly smooth, restaurant-quality texture.
Adding Cream and Seasonings
Return the soup to the pot if you used a blender or sieve. Stir in the heavy cream, which adds richness and helps create that signature velvety texture. The cream should be added off the heat to prevent curdling.
Season the soup with salt, white pepper, and a pinch of nutmeg. White pepper is traditional in French cooking for light-colored soups as it doesn’t leave dark specks, but black pepper works fine if that’s what you have.
Taste and adjust the seasoning as needed. The soup should be well-balanced with the sweet leek flavor coming through clearly, supported by the creamy richness of the potatoes and cream.
Final Touches and Garnishing
Stir in most of the fresh chives and parsley, reserving some for garnish. The fresh herbs add brightness and color that balances the rich, creamy soup. Add them just before serving to maintain their vibrant color and fresh flavor.
If the soup seems too thick, thin it with a little more broth or milk. If too thin, simmer uncovered for a few minutes to reduce and concentrate the flavors. The consistency should be creamy but not overly thick.
Serving and Presentation
Ladle the hot soup into warmed bowls for the best presentation and to keep the soup at the optimal temperature. A warm bowl prevents the soup from cooling too quickly and enhances the overall dining experience.
Garnish each serving with a sprinkle of the reserved fresh herbs, a light drizzle of good olive oil, and perhaps a few homemade croutons for textural contrast. A small swirl of cream or a dollop of crème fraîche adds elegant visual appeal.
Accompaniment Suggestions
Serve the soup with crusty French bread, dinner rolls, or homemade croutons for dipping and added substance. A simple green salad with vinaigrette makes a nice light accompaniment that cuts through the soup’s richness.
For a more substantial meal, consider serving smaller portions as a starter before roasted chicken, grilled fish, or a cheese and charcuterie board. The soup’s neutral flavors complement many main courses.
Variations and Enhancements
For extra flavor depth, try adding a splash of white wine when cooking the leeks, allowing it to cook off before adding the broth. Some cooks enjoy adding a small amount of roasted garlic for more complex flavors.
Bacon or pancetta can be cooked with the leeks for a heartier version, while vegetarians might appreciate the addition of roasted mushrooms or a sprinkle of truffle oil for earthiness.
Storage and Reheating
This soup keeps beautifully in the refrigerator for up to 5 days and actually improves in flavor as the ingredients continue to meld. Store it covered and reheat gently over medium heat, stirring occasionally.
The soup can be frozen for up to 3 months, though the texture may change slightly due to the cream. If freezing, consider adding the cream when reheating rather than before freezing for the best results.
Make-Ahead Tips
The soup can be made completely ahead through the pureeing stage, then the cream and herbs added when reheating for serving. This makes it perfect for entertaining when you want to prepare courses in advance.
The base vegetables can even be cooked and refrigerated a day ahead, then combined with broth and simmered when ready to finish the soup, making this an excellent option for meal planning.
