This easy 4 Ingredient Potato and Leek Soup recipe is all you need for weeknight dinners when the weather is chilly. It’s a silky smooth potato soup that tastes tons richer than you’d expect with just four ingredients.
As with many things, you can always make it more complicated, and I’ve added some suggestions. But this humble 4 ingredient potato soup recipe is a great illustration of how you can use fresh ingredients prepared simply to create something that is so much more.
This 4-ingredient recipe is inspired by the Potage Parmentier (Leek and Potato Soup) from Julia Child’s Mastering the Art of French Cooking. In fact, her potato and leek soup is the original 4 ingredient potato soup if you exclude her parsley or chive garnish.
When I first posted this recipe, I made it only with Yukon Gold potatoes. Yukon Gold potatoes are particularly good if you are want chunks of potatoes like in this corn and bacon soup. Russet or baking potatoes are starchier and are the best for mashed potatoes, French fries, and latkes.
I decided to poll the Soup Lovers Facebook group which potato these soup experts use in their potato soups. And, to my surprise, there was a pretty equal split. After trying it, I think the best potatoes for potato soup are a combination of potatoes, just like the best apple pie will use a combination of apple varietals.
Leeks have a sweeter and more subtle flavor than yellow onions. If you don’t have leeks, you can sub a sweet onion like a Vidalia or Walla Walla onion in a pinch. The only fussy step in the recipe is with the leeks because they tend to accumulate dirt as they grow.
How to clean leeks
The four panels below show you how to clean leeks. First trim the ends of the leek (Panel #2, below).
Next, make a partial cut running lengthwise from top to bottom of the leek (Panel #3). Spread the layers apart to look for dirt (Panel #4) and run the leek under the faucet to clean. Easy!
Please see the recipe card below for complete information on ingredients and quantities.
Variations and substitutions
This is one time where a recipe with a small number of ingredients truly doesn’t need anything more. But, if you want to, here are a few suggestions:
- Use some other member of the onion family like sweet onions or even garlic.
- Use sweet potato instead of or with the potato.
- Add cauliflower to make a cauliflower, leek, and potato soup. Or add broccoli.
- Use vegetable or chicken broth in place of the water.
- Add herbs and spices like pepper or nutmeg.
- Add cream to finish.
- Add a cup of cheddar or other cheese.
- Add a garnish or two like parsley, chives, green onion, cheese, or crisped bacon.
Recipe tips and tricks
The 4-ingredient potato soup comes together in 45 minutes, most of which is hands off time. Vegetable soups are really quick to make and great for weeknight dinners.
Step 1: Melt the butter in a soup pot and cook the sliced leeks over low heat until they are soft and just beginning to brown (Panels #1 and #2 below).
Step 2: Add the potatoes and salt and stir for a minute or so (Panel #3).
Step 3: Cover the vegetables with water, put the lid on the pot, and let it simmer (Panel #4).
Step 4: Once the potatoes are soft, purée the mixture and then return it to the soup pot to rewarm (Panel #5). Serve hot, warm, or even cold!
If you use a hand-held stick blender to purée soups, please make sure to unplug it before you clean it! You can read more about this and other hazards in the kitchen from a doctor’s perspective.
What to serve with this 4-ingredient potato soup
Serve this soup with:
Yes. Soups freeze perfectly as long as you haven’t added cream, which can separate in the process of freezing and reheating. Just reheat your frozen soup gently in the microwave or a small pot with a little extra water.
Sure, it’s still a 4 ingredient potato soup if you only purée half the soup. But you’ll want to pay closer attention to how you slice the potatoes and leeks so that you have bite-sized pieces.
Of course, simply sub out the butter for olive oil and top with your favorite garnishes.
Related soup recipes
Like potatoes and onions? Check out these recipes using one or the other:
Love this recipe? Please leave a 5-heart 💜💜💜💜💜 rating in the recipe card below. Let me know how much you loved it, or any problems you had, in the comments section further down.
4 Ingredient Potato and Leek Soup
- Blender or food processor
- 3 tablespoons (1.5 ounces) butter
- 2 leeks, cleaned and sliced
- 3 Yukon Gold potatoes (about 1.5 pounds), peeled and chopped
- 1 teaspoon salt
- Melt the butter in a soup pot over low heat.3 tablespoons (1.5 ounces) butter
- Add the sliced leeks and cook until softened and just beginning to brown, about 10 minutes.2 leeks, cleaned and sliced
- Add the potatoes and salt and stir to mix.3 Yukon Gold potatoes (about 1.5 pounds), peeled and chopped, 1 teaspoon salt
- Cover the vegetables with water, about 4 cups, cover the pot, and simmer for about 30 minutes until you can pierce the potatoes easily with a fork.
- Remove the pot from heat and let the potato soup cool briefly before puréeing in the blender or food processor. Return the soup to the pot and rewarm gently.
Are you an adventurous home cook looking for inspiration in your weeknight meals and weekend baking?