Clean the Mussels: 

Rinse the mussels under cold water, scrubbing off any debris. Remove the beards by pulling them gently away from the shell. Discard any mussels with broken shells or those that do not close when tapped.

Prepare Ingredients: 

Heat the olive oil in a large pot over medium heat. Add the sliced leeks, chopped onion, and minced garlic. Sauté until the vegetables are soft and fragrant, about 5 minutes. 

Cook Mussels: 

Pour in the white wine and bring it to a simmer. Add the cleaned mussels to the pot and cover with a lid. Cook for about 5-7 minutes, shaking the pot occasionally, until the mussels have opened. Discard any mussels that remain closed.

Add Cream and Seasoning: 

Once the mussels have opened, pour in the heavy cream and stir gently to combine. Season with salt and pepper to taste. Let the mixture simmer for another 2-3 minutes until the sauce thickens slightly.

Garnish and Serve: 

Sprinkle the chopped fresh dill over the mussels and sauce. Give it a final gentle stir. Serve the mussels hot with crusty bread on the side for dipping into the creamy sauce.