Heat oil in a large pan on medium heat, sauté the onion for a few minutes until translucent but do not brown it. Add the garlic and thyme, and cook for another 30 seconds while stirring to prevent the garlic from burning.

Pour in the stock and bring it to a boil; reduce it to a simmer for 5 minutes or until the stock has reduced by half. Add the cream, season to taste with salt and pepper, and add the lemon juice.

Add the mussels to the pan and cover with a lid. Allow the mussels to cook for 5 minutes. Stir in the dill and lemon zest. Serve topped with fresh parsley and Parmesan cheese.

Heat oil in a large pan on medium heat, sauté the onion for a few minutes until translucent but do not brown it. Add the garlic and thyme, and cook for another 30 seconds while stirring to prevent the garlic from burning.

Pour in the stock and bring it to a boil; reduce it to a simmer for 5 minutes or until the stock has reduced by half. Add the cream, season to taste with salt and pepper, and add the lemon juice.

Add the mussels to the pan and cover with a lid. Allow the mussels to cook for 5 minutes. Stir in the dill and lemon zest. Serve topped with fresh parsley and Parmesan cheese.