Cold evening. Bare fridge. Zero motivation.
Sound familiar? This soup was born on exactly that kind of night, and it turned out to be one of those recipes I’ve made on repeat ever since.
Potato leek soup sounds simple, and it is. But simple doesn’t mean boring. Done right, it’s rich, silky, deeply savory, and the kind of thing you’ll be thinking about the next morning.
And here’s the part that surprises most people: leeks are doing most of the heavy lifting here. They’re sweet, mild, and when cooked down slowly, they almost melt into the broth and give it a depth that you honestly can’t get from onions alone.
Keep reading, because there are a few things most recipes don’t tell you that will completely change how yours turns out.
What You’ll Need
Ingredients
- 3 large leeks (about 900g / 2 lbs), white and light green parts only
- 4 medium Yukon Gold potatoes (about 700g / 1.5 lbs), peeled and cubed
- 3 tablespoons unsalted butter
- 3 cloves garlic, minced
- 1 litre (4 cups) good-quality chicken or vegetable broth
- 1 cup (240ml) heavy cream
- 1 teaspoon fresh thyme leaves (or ½ tsp dried thyme)
- 1 bay leaf
- Salt and black pepper, to taste
- Fresh chives, chopped, for serving
- Optional: a drizzle of good olive oil or sour cream, for serving
Tools You’ll Need
- Large heavy-bottomed pot or Dutch oven
- Immersion blender (or a regular blender with a heat-safe jug)
- Sharp chef’s knife and cutting board
- Colander or large bowl (for washing the leeks)
- Wooden spoon
- Ladle
- Measuring cups and spoons
Pro Tips
- 🧅 Wash leeks properly. Leeks hide grit between their layers and it will ruin an otherwise perfect soup. Slice them first, then soak in a big bowl of cold water, swish them around, and lift them out. The dirt sinks to the bottom.
- 🧈 Don’t rush the leeks. Give them a good 10 minutes on medium-low heat in butter until they’re completely soft and sweet. This is where the flavor comes from. Skipping this step makes the soup taste flat.
- 🥔 Use Yukon Gold potatoes, not Russets. Yukon Golds have a naturally buttery, creamy texture. Russets turn gluey and starchy when blended.
- 🫙 Blend in batches if using a regular blender. Hot liquid expands. Fill it no more than halfway, hold the lid down with a folded dish towel, and blend slowly. Don’t learn this the hard way.
- 🧂 Season at the end, not just the beginning. The flavor of the soup concentrates as it simmers. Taste and adjust salt and pepper after blending, right before serving.
How to Make Potato Leek Soup
- Prep the leeks. Trim the dark green tops and roots. Slice the white and light green parts into thin half-moons. Transfer to a large bowl of cold water, swish to release any grit, and lift out. Drain on paper towels.
- Cook the leeks. Melt butter in a large pot over medium-low heat. Add the leeks and a pinch of salt. Cook, stirring occasionally, for 10-12 minutes until soft, silky, and slightly golden. Add garlic and thyme, and cook for another 2 minutes.
- Add the potatoes and broth. Add the cubed potatoes, broth, and bay leaf. Bring to a boil, then reduce heat and simmer for 18-20 minutes, or until the potatoes are completely fork-tender.
- Remove the bay leaf. Fish it out and discard it before blending. (You only need to do this once to remember why it matters.)
- Blend. Use an immersion blender directly in the pot and blend until smooth. If using a regular blender, blend in batches. For an ultra-silky texture, you can strain it through a fine mesh sieve, but it’s optional.
- Stir in the cream. Return the soup to low heat if needed. Pour in the heavy cream, stir to combine, and taste for seasoning. Add more salt, pepper, or a squeeze of lemon juice if it needs brightness.
- Serve. Ladle into bowls. Top with fresh chives, a drizzle of olive oil or a small spoonful of sour cream. Crusty bread alongside is non-negotiable in my house.
Substitutions and Variations
| Ingredient | Swap | Notes |
|---|---|---|
| Heavy cream | Coconut cream or cashew cream | Great dairy-free option; coconut adds a subtle sweetness |
| Butter | Olive oil or vegan butter | Works perfectly for a dairy-free or vegan version |
| Chicken broth | Vegetable broth | Keeps it fully vegetarian or vegan |
| Yukon Gold potatoes | Red potatoes | Similar creamy texture; avoid Russets |
| Fresh thyme | Rosemary or dried thyme | Rosemary gives a slightly more robust flavor |
Want to add some texture? Keep a small portion of the soup un-blended before you blend the rest. Stir the chunky portion back in at the end. You get the best of both worlds.
Love it extra rich? Stir in a knob of butter right at the end, off the heat. It gives the soup a glossy, restaurant-style finish.
Spice it up: Add a pinch of cayenne or a drizzle of chili oil when serving. The heat plays surprisingly well against the creaminess.
Make-Ahead Tips
This soup is a fantastic make-ahead meal. Here’s what to know:
- Make the soup up to 3 days in advance. Store in an airtight container in the fridge.
- For best results, hold off on adding the cream until you reheat and serve. It keeps the base brighter and extends fridge life.
- Reheat gently on the stovetop over medium-low heat. Don’t boil it after the cream has been added or it can separate.
- Freeze the base (without cream) for up to 3 months. Thaw overnight in the fridge, reheat, and add cream fresh.
Nutritional Breakdown
Per serving (based on 4 servings, made with heavy cream):
| Nutrient | Amount |
|---|---|
| Calories | ~340 kcal |
| Carbohydrates | ~36g |
| Protein | ~6g |
| Fat | ~20g |
| Fiber | ~3g |
| Sodium | ~520mg (varies by broth) |
To lighten it up, swap heavy cream for half-and-half or whole milk. It’ll be slightly less rich, but still very good.
What to Serve With It
This soup is a meal on its own, but these pairings take it up a notch:
- Crusty sourdough bread for dipping (the obvious choice, and for good reason)
- A simple green salad with a sharp vinaigrette to balance the richness
- Grilled cheese sandwich for a full comfort food moment
- Roasted chicken if you want to make it a heartier dinner
Leftovers and Storage
- Fridge: Store in an airtight container for up to 4 days. The flavor actually deepens overnight.
- Freezer: Freeze the base (cream-free) for up to 3 months. Label it with the date.
- Reheating: Stovetop over medium-low heat, stirring occasionally. Add a splash of broth or water if it’s thickened too much in the fridge. Skip the microwave if you can, it heats unevenly.
- If the texture looks grainy after reheating: A quick blitz with the immersion blender brings it right back together.
FAQ
Can I use the dark green tops of the leeks?
They’re very tough and fibrous and won’t soften properly, so skip them in this recipe. You can save them for homemade stock though, they work great there.
Do I have to blend it smooth, or can I leave it chunky?
Totally up to you. For a rustic, heartier version, only blend half the soup and stir it back into the pot. For silky and smooth, blend the whole thing.
My soup turned out too thin. How do I fix it?
Simmer it uncovered for another 10-15 minutes to reduce and thicken. You can also add one or two more cooked potato chunks before blending.
My soup turned out too thick. Help.
Just add more broth or water, a little at a time, and stir over low heat until you hit the consistency you want.
Can I make this vegan?
Yes! Use olive oil instead of butter, vegetable broth, and swap the heavy cream for full-fat coconut cream or cashew cream. It’s genuinely delicious.
Is it supposed to taste sweet?
A little, yes. Leeks have a natural sweetness that’s much more gentle than onions. It balances the savory broth and cream really well. If your soup tastes overly sweet, it might need more salt and a squeeze of lemon juice to balance it out.
Wrapping Up
Potato leek soup is one of those recipes that looks unassuming on paper but genuinely surprises people when they taste it.
It’s the soup that gets requested again. The one you make when someone’s had a rough week. The one you meal prep on a Sunday and feel unreasonably proud of for the rest of the week.
And the good news? It’s genuinely simple. No fancy techniques. No hard-to-find ingredients. Just a pot, a blender, and about 45 minutes.
Give it a try, and when you do, drop a comment below and let me know how it turned out. Did you change anything? Add a fun topping? Make it vegan? I’d love to hear what version ended up in your bowl.