Save My grandmother kept a handwritten recipe card for potato leek soup tucked behind her stove, the paper soft and stained from years of use. One afternoon, watching her slice leeks with practiced ease, she mentioned that this soup taught her patience—not the quiet kind, but the sort that fills a kitchen with steam and softens everything it touches. I've since made it dozens of times, and each batch feels like a small conversation with her, especially on days when the weather turns cool and the house needs warming from the inside out.
I made this for a friend who'd just moved into her first apartment, and she cried a little when she tasted it—not from sadness, but from that specific relief of finding something warm and familiar in an unfamiliar place. She now texts me photos of her own batches, and I love that this soup has become part of her kitchen story too.
Ingredients
- Leeks (3 medium, white and light green parts): These are the soul of the soup, far gentler than regular onions once cooked down. The key is cleaning them thoroughly between layers where grit loves to hide—slice them lengthwise first, then fan the layers under running water.
- Unsalted butter (2 tablespoons): This creates the foundation for flavor; it lets the leeks and onions release their sweetness without competing with salt you can't control.
- Yellow onion (1 medium, diced): Adds depth and a subtle sweetness that balances the leek's delicate flavor—don't skip it even though leeks are the star.
- Yukon Gold potatoes (3 medium, peeled and diced): These break down into a natural creaminess that makes the soup luxurious without heavy cream alone. Their waxy texture holds together better than floury varieties.
- Garlic (2 cloves, minced): Just enough to whisper in the background; too much drowns out everything else you've carefully built.
- Vegetable broth (4 cups): Use the low-sodium version so you control the seasoning—store-bought broth can be surprisingly salty.
- Whole milk or heavy cream (1 cup): Cream makes it richer, milk keeps it lighter; both are right depending on your mood.
- Bay leaf (1): Infuses a subtle herbal note that ties everything together.
- Salt, black pepper, and nutmeg: The nutmeg is optional but transforms the soup into something almost elegant—just a whisper of it.
- Fresh chives or parsley (2 tablespoons): A bright garnish that cuts through the richness and reminds you this soup is alive.
Instructions
- Clean and slice your leeks:
- Slice them lengthwise down the middle, then separate the layers slightly and rinse under running water to catch any hidden grit between them. Once clean, slice them into thin half-moons.
- Sauté the leeks and onion:
- Melt butter in a large pot over medium heat until it foams. Add your leeks and diced onion, stirring occasionally for about 7 minutes until they're soft and translucent but haven't taken on any color. The pot should smell sweet and gentle.
- Add garlic and let it bloom:
- Toss in the minced garlic and cook for just 1 minute—long enough to wake up the aroma but not so long it turns bitter or brown.
- Build the broth base:
- Stir in your diced potatoes, add the bay leaf, and pour in the vegetable broth. Bring everything to a gentle boil, then turn the heat down to a simmer and cover the pot. Let it bubble quietly for 20 to 25 minutes until the potatoes are fall-apart tender when you poke them.
- Blend into creaminess:
- Remove the bay leaf and use an immersion blender to purée the soup until it's smooth and luxurious. If you don't have an immersion blender, carefully ladle the soup into a regular blender in batches, blend, and return it to the pot.
- Finish with cream and seasoning:
- Stir in your milk or cream and heat gently until steaming—never let it boil or the dairy can separate. Taste and add salt, pepper, and a pinch of nutmeg if you like, adjusting until it tastes right to you.
- Serve with intention:
- Ladle into bowls, scatter chives or parsley across the top, and add a swirl of cream or olive oil if you want to be fancy about it.
Save There's a moment about halfway through cooking when your kitchen fills with this warm, sweet smell that somehow feels both humble and comforting. That's when you know you're making something that matters, something people will remember.
Why This Soup Keeps Well
Potato leek soup improves with time in a way that defies logic. The flavors deepen and marry together overnight, so if you're making this for a dinner party, feel free to prepare it the day before. Just store it in an airtight container in the refrigerator and reheat gently on the stove with a splash of broth or milk to restore its silky texture.
The Leek: A Vegetable with History
Leeks are the unsung vegetables of the soup world, overlooked by people who think they're just overgrown scallions. Once you've tasted what they become when cooked gently in butter, you'll understand why this soup shows up in kitchens across France, Wales, and anywhere else that values simple, honest food. They're sweeter than onions, more substantial than garlic, and somehow make you feel taken care of when you eat them.
Making It Your Own
This recipe is a foundation, not a rulebook. I've added a splash of white wine after sautéing the leeks, which brings a subtle brightness that's wonderful on heavier days. Some friends swear by a pinch of thyme or a smidge of truffle oil for special occasions. The beauty of this soup is that it accepts improvisation gracefully, so taste as you go and trust your instincts.
- Try stirring in some crispy bacon bits or pancetta at the end if you're in a non-vegetarian mood.
- A drizzle of good olive oil or a dollop of crème fraîche on top elevates it instantly.
- Leftovers freeze beautifully for up to three months, so double the batch when you make it.
Save This soup has become my kitchen's quiet hero, the thing I make when I want to slow down and remember why cooking matters. It asks very little and gives so much back.
Recipe FAQs
- → How do I clean leeks properly?
Slice leeks lengthwise and cut into thin half-moons. Place in a bowl of cold water and swish vigorously, letting the grit settle to the bottom. Lift leeks out, leaving the dirt behind. Repeat if necessary until water runs clear.
- → Can I freeze this soup?
Yes, though the texture may change slightly. Freeze without the cream or milk added. When reheating, add the dairy fresh. The soup will keep well for up to 3 months in the freezer in an airtight container.
- → What potatoes work best?
Yukon Gold potatoes are ideal for their naturally creamy texture and buttery flavor. Russets also work well and break down more easily for an even smoother result. Avoid waxy potatoes like red or new potatoes as they won't soften sufficiently.
- → How can I make it dairy-free?
Substitute butter with olive oil for sautéing. Use coconut milk, almond milk, or oat milk instead of dairy cream. The soup will still be delicious and velvety, though the flavor profile will shift slightly depending on your milk alternative.
- → Why is my soup watery?
If the consistency is too thin, simmer uncovered for 10-15 minutes to reduce. Alternatively, mash some of the potatoes against the side of the pot before blending, or add an extra peeled potato and simmer until it breaks down completely.
- → What can I serve with this?
Crusty bread, warm baguette slices, or homemade croutons are perfect for dipping. A simple green salad with vinaigrette balances the richness. For heartier meals, pair with a quiche or grilled cheese sandwich.