This cozy Vegan Potato Leek Soup is silky, smooth, and full of flavor. It's a light, yet satisfying soup—made without dairy or coconut milk. One-pot, easy to make, and leftovers keep well. Delicious paired with crusty bread, for dipping.
Quick soak cashews: Add cashews to a heatproof bowl and cover with boiling water. Let sit for at least 10 minutes to soften.
Start cooking soup: Meanwhile, melt butter in a large pot over medium heat. Add leeks and garlic, and cook, stirring frequently, until leeks are soft but not yet browning at the edges, about 10 minutes.
Blend cashews: Drain cashews. Add drained cashews and broth to a blender. Blend until completely smooth.
Combine and simmer: Add blended cashew mixture, potatoes, bay leaves, salt, and pepper to the pot. Cover with the lid slightly ajar and bring to a boil over high heat. Once boiling, reduce to a simmer, and cook until potatoes are soft when poked with a fork, about 10 minutes.
Blend and finish seasoning: Transfer the soup to a blender and blending just until smooth, no longer than 1 minute (see note 4). Transfer soup back to the pot, over low heat to keep warm. Stir in lemon juice (if using) and nutmeg. Taste and season with more salt and pepper if needed. Ladle into bowls and garnish with chives, if using.
Potatoes: We use Russet potatoes for this soup. They are high-starch potatoes, so will fall apart quite easily after cooking and thicken up the soup nicely. Alternatively, you could substitute Yukon Gold potatoes which are considered medium-starch potatoes (they will add a bit more yellow color to the soup).
Lemon Juice: A small splash of acid can really brighten the flavor in a dish. We recommend adding a bit of fresh lemon juice at the end for this reason. But, if you don't have any, you can leave it out. The soup will still taste good.
Blending soup: Potatoes can get gluey/gummy when over-blended. Stop blending as soon as the soup is creamy; and avoid blending longer than 1 minute. Be careful when blending hot soups—avoid overfilling the blender (work in batches if needed); and ensure there's a way for steam to escape (the lid for high speed blenders usually has this built in). If you have an immersion blender, you can use that instead.
Serving suggestions: This soup can be enjoyed hot or chilled. It is delicious served with bread on the side!