Start by washing the leeks thoroughly to remove any dirt.

Slice them and chop the onion to create a flavor base for the soup.

In a large pot, heat the olive oil over medium heat.

Add the chopped onion and sliced leeks to the pot. Cook for about 5 minutes, stirring occasionally until they soften.

Stir in the diced potatoes and cook for an additional 2 minutes.

Add the vegetable broth and bring it to a boil.

Reduce the heat and let the soup simmer for about 20 minutes.

Using an immersion blender, puree the soup until smooth.

Stir in the heavy cream and season with salt and pepper.