This leek and potato soup recipe is a classic French dish that is thick, creamy, velvety and incredibly satisfying. A bowl of goodness that is easy to make with just a handful of ingredients. Potato leek soup can easily be served as an appetizer or a stand alone lunch meal. Simple, yet delicious and elegant, this French soup recipe is made with fragrant leeks simmered in a vegetable stock with tender potatoes and finished with a splash of cream.
Origin of potato and leek soup
Leek and potato soup, also known as ‘Potage Parmentier’ in French has its origin in France. The soup was named after Antoine-Augustin Parmentier, a French pharmacist and agronomist who lived in the 18th century. He heavily promoted potatoes as an important food source, as during that time in France, potatoes were not considered very popular.
He started hosting dinners for celebrities of the time serving dishes featuring potatoes as a main ingredient, like hachis Parmentier (which is the French version of cottage pie), salade Parmentier (potato salad) and this potage Parmentier. The original ingredients of this soup were leeks, potatoes, cream, water and salt simmered and puréed.
Which ingredients to use
- Leeks: Choose fresh leeks with vibrant green leaves and a white pale stalk that have a firm feel. For this leek soup recipe we will only use the white and light green parts.
- Potatoes: Use potatoes with a nice creamy and buttery flavor like Yukon Gold, but you can also use a more starchy potato like Russets, according to personal preference.
- Butter: I prefer butter to sauté the leeks to bring out the lovely fragrant and aromatic taste. You can consider using olive oil, cooking oil or a combination of butter and oil.
- Garlic: For giving the soup extra depth of flavor. Garlic powder can be used as an alternative.
- Stock: Vegetable stock has my preference for this potato soup recipe as the flavors work better. Chicken stock works too if that is what you have or prefer using.
- Cream: A splash of heavy cream to finish off the soup and make it more creamy and velvety.
- Salt and pepper: As potato and leek soup can taste a bit bland, use enough salt and pepper to bring some extra flavor to this dish. As for pepper, use white pepper to avoid having black dots in the soup (from the black pepper).
- Herbs: Add a bay leaf and fresh or dried thyme for some extra herby flavor. Or a bouquet garni.
How to make potato leek soup
Note: All the exact quantities of the ingredients can be found in the recipe card at the bottom of this post.
This soup recipe comes together fairly easily. As leeks are similar to onions and have a strong pungent flavor, the key for this soup is to take your time to slowly sauté the leeks until soft to release their aromatic flavors.
- Clean the leeks: Leeks are a great ingredient to use in many meals, but they do need proper cleaning. Sand and dirt gets stuck between their layers as they grow. First cut off the dark green leaves then slice the light green part lengthwise in half. Rinse the leek stalk under cold running water, separating the different layers with your hands until all dirt is washed out. Pat dry and finely slice the leeks.
- Prepare the potatoes and garlic: Peel the potatoes and cut in small equally sized cubes to allow for even cooking. Peel and mince the garlic.
- Sweat the leek: Melt butter in a large soup pot over medium heat and sauté the leeks for 5 minutes until softened and fragrant. Make sure to keep stirring and to keep the heat low enough so they don’t turn golden or brown but soft and sweet instead.
- Add the other ingredients: When the leek is softened, add the potatoes and garlic and stir well. Then pour in the stock and add the bay leaf, thyme, salt and pepper.
- Simmer the soup: Cover the pot and bring to a boil. Reduce the heat to medium-low and simmer for 20 minutes until the potatoes are soft. Check with a fork to make sure the potatoes are soft enough to blend, if not, continue cooking.
- Purée the soup: Remove the pot from the heat and remove the bay leaf or bouquet garni. Purée the soup with a stick or hand blender until smooth and velvety.
- Add the cream: Add the cream and gently stir until well combined. Add more water or stock if the consistency is too thick.
- Finish the soup: Heat the soup again before serving and season with salt and pepper to taste.
- Garnish: Serve with optional garnish like chives, parsley, thyme, croutons, crispy bacon bits or a dollop of fresh cream.
Can I use frozen leeks?
While preference goes to fresh leeks as more flavor will be released for this soup, frozen leeks are a great option when fresh leeks are not available or not in season. Add frozen leeks to the melted butter and sauté until all the moisture has evaporated and the leeks start sweating and turning fragrant and soft.
Can I use onions instead of leek?
Leeks belong to the same Allium family group as onions which often work as a great substitute for leeks when leeks are not available. However, as leeks are a main ingredient in this particular recipe, onions are not a suitable alternative in this case.
Can you freeze leek and potato soup?
Yes, you can freeze this leek and potato soup but you will want to freeze it before adding the cream. Even though you can freeze the soup when the cream is already added, you need to take into account that the consistency can change and the fat of the cream can separate after thawing.
So just add the fresh cream after thawing, then reheating the soup.
More creamy soup recipes to try
- Classic pumpkin soup
- Eggplant soup with roasted chickpeas
- Yellow bell pepper soup with coconut and curry
- Creamy yellow pepper soup
- Carrot and ginger soup
More recipes using leek to try
Leek and potato soup (Potage Parmentier)
- 2 tablespoons salted butter
- 1 pound (450 gram) potatoes
- 4 cups (450 gram) leeks cleaned and chopped
- 2 cloves garlic
- 5 cups (1.2 liter) vegetable stock
- ½ cup (120 ml) heavy cream
- 1 bay leaf
- 1 teaspoon thyme
- salt and white pepper to taste
- Peel and dice the potatoes. Trim the ends of the leeks, cut the top in half and wash under cold running water until all the sand is removed. Then finely slice the leeks but only the white and light green parts.
- Melt butter in a large pan over medium heat. Sauté the leeks for 5 minutes until softened. Keep stirring while sweating the leeks to make sure they don't burn as you want a light colored soup.
- Add the potatoes and garlic and mix together. Pour in the stock, then add the bay leaf, thyme, salt and pepper and cover with a lid. Turn up the heat slightly and gently simmer for 20 minutes until the potatoes are soft.
- Turn off the stove and remove the pot from the heat. Remove the bay leaf and mix with a stick blender until smooth. Add more stock or water if the consistency is too thick.
- When the soup is blended, stir in the cream.
- Serve warm.