Potato Leek Soup

I’m so excited to share my Potato Leek Soup with you! This is the cozy, silky soup I turn to when I want something simple, warming, and veggie-forward. It’s buttery, tender, and brightened with a splash of lemon — perfect with crusty bread or a grilled cheese. I’ll walk you through every step so it’s easy, even if you’ve never cooked leeks before.

Level: Easy
Total Time: 45 minutes
Prep Time: 15 minutes
Cook Time: 30 minutes
Yield: 8 servings
Course: Soup
Cuisine: Classic / Comfort

I started making potato leek soup after bringing home a huge bunch of leeks from the farmers’ market — their mild, sweet onion flavor is perfect in a soup. This version is creamy and full-flavored, but it doesn’t rely on a ton of fancy ingredients. You can make a quick leek-top broth for extra depth (I’ll show you how), or use good-quality vegetable broth if you’re short on time. Either way, the method is the same: soften the leeks, simmer the potatoes until they’re pillowy, blend until silky, then stir in a little milk or cream and lemon to finish.

Description

Why this soup works:

• Leeks add a gentle, sweet onion flavor without being sharp.
• Yukon Gold (yellow) potatoes turn naturally creamy when cooked and blended — no heavy cream needed for body.
• Optional leek-top broth intensifies the soup with an oniony, aromatic stock made from the greens you’d otherwise toss.
• A quick blend (immersion or stand blender) makes it smooth and luxurious.
• A splash of lemon at the end brightens the whole bowl.

Ingredients

For the soup:

• 4 large leeks (use the white and light green parts only), cleaned and sliced
• 3 tablespoons unsalted butter (or olive oil for vegan)
• 1 teaspoon sea salt, plus more to taste
• Freshly ground black pepper
• 2 pounds Yukon Gold potatoes, chopped into roughly 1–1½ inch pieces (no need to peel if you prefer)
• 3 garlic cloves, grated or finely minced
• 6 cups leek-top broth (see below) or good-quality vegetable broth
• 3 sprigs fresh thyme (tied together) or 1 teaspoon dried thyme
• 1 cup milk or heavy cream (2% or whole milk works too; use oat milk for dairy-free)
• 1 tablespoon fresh lemon juice (optional, but highly recommended)
• Chopped fresh chives or parsley for garnish

Optional — Leek Top Broth (makes ~12 cups; use 6 cups for the soup):

• Dark green tops from 4 large leeks (washed well)
• 12 cups water
• 8 sprigs fresh thyme
• 5 garlic cloves, smashed
• 1 tablespoon sea salt
• 1 tablespoon whole black peppercorns

Directions

Make the leek-top broth (optional, but tasty)

1. Chop the dark green leek tops roughly and put them in a large pot with water, thyme, smashed garlic, salt, and peppercorns.
2. Bring to a boil, then lower heat and simmer 30 minutes.
3. Strain the broth through a sieve into a bowl or large measuring cup. Measure 6 cups for the soup and save extra for another use.

Make the soup

1. Prep the leeks properly (important): slice the white and light green parts in half lengthwise, then rinse the layers under running water to remove grit. Slice thinly after rinsing.
2. Sauté the leeks: In a large heavy pot or Dutch oven, melt the butter over medium heat. Add sliced leeks, 1 teaspoon salt, and several grinds of black pepper. Cook gently, stirring occasionally, until the leeks are soft and sweet (not browned), about 8–10 minutes. If they start to brown, lower the heat.
3. Add potatoes, garlic, broth, and thyme: Stir in the chopped potatoes and grated garlic, then pour in 6 cups of broth and add the thyme bundle. Bring to a simmer, then reduce heat and cook uncovered about 20 minutes, or until potatoes are very tender and fall apart easily with a fork.
4. Remove thyme and blend: Remove the thyme bundle. Use an immersion blender to purée the soup until smooth (my favorite method). If using a stand blender, cool slightly and blend in batches — never fill the blender more than halfway and vent the lid with a towel to avoid steam explosions.
5. Finish with milk and lemon: Return the puréed soup to the pot (if needed) and stir in the milk or cream. Warm gently — do not boil after adding dairy. Add the lemon juice to brighten the flavor. Taste and adjust salt and pepper.
6. Serve: Ladle into bowls and top with chopped chives and a few grinds of black pepper. Serve with crusty bread.

Process Details

• Washing leeks: they hide grit between layers. Slice them then rinse under running water, gently separating the layers. Dirty leeks = gritty soup.
• Why Yukon Gold: their flesh breaks down into a silky base when cooked and blended — that’s what gives the soup body without excess cream.
• Blending safety: hot liquids expand — blend in small batches or use an immersion blender to avoid splashes. Cover the blender lid loosely and hold a towel over it.
• Lemon at the end: a little acid wakes up the flavors and stops the soup tasting flat.

Tips for Success

• Don’t skip washing leeks. Even pretty leeks can be sandy inside.
• Keep the heat low when sweating leeks. You want softness and sweetness, not browning.
• No peeling needed. If you like a bit more fiber and color, leave the potato skins on after a good scrub.
• Adjust thickness: If the soup is too thick, stir in a little extra broth or water. If too thin, simmer a few minutes uncovered or mash a cup of the cooked potatoes into the pot.
• Dairy-free: Use oat or unsweetened soy milk in place of cream, and swap butter for olive oil.
• Make-ahead: The soup tastes great the next day; refrigerate for up to 3 days.

Serving Ideas

• Classic: a slice of crusty country bread or sourdough.
• Comfort combo: pair with a grilled cheese for dunking.
• Light side: a simple green salad with a lemon vinaigrette.
• Garnishes: chopped chives, cracked black pepper, a drizzle of olive oil, or a spoonful of plain yogurt (or dairy-free yogurt).

Storage & Freezing

• Refrigerator: Store in an airtight container for up to 3 days. It will thicken as it cools — thin with a splash of broth or water when reheating.
• Freezing: I generally don’t recommend freezing potato-based soups because the texture can change (they may get grainy). If you must, freeze without the dairy for up to 3 months; thaw overnight and stir in milk or cream when reheating.

Nutrition Info (approximate per serving)

• Makes ~8 servings.
• This is a vegetable-forward, moderately creamy soup — calories and macros will vary based on milk/cream choice and whether you peel potatoes. (If you want a rough calorie estimate, tell me which milk you’ll use and I’ll calculate it.)

This Potato Leek Soup is simple, forgiving, and reliably comforting. Once you get the hang of cleaning leeks and cooking the potatoes until they’re falling-apart soft, the rest is blending and a quick finish with milk and lemon. It’s great for weeknights, makes lovely leftovers, and is a perfect way to showcase seasonal leeks. If you want, I can format this into a printable recipe card or make a veggie-forward, lower-calorie version next — which would you prefer?