Prepare the leeks by cleaning thoroughly, slicing thinly, and setting aside. Peel and cube the potatoes.

In a large pot over medium heat, melt the butter until bubbly. Add leeks and sauté for about 5 minutes until soft.

Toss in cubed potatoes and pour in vegetable broth. Bring to a boil, then reduce heat and simmer for 20 minutes until potatoes are tender.

Use an immersion blender to puree the mixture until smooth. For a chunkier texture, blend less.

Return to low heat, stir in cream, salt, and pepper to taste. Mix well.

Ladle into bowls and serve hot with crusty bread or croutons on top.