Chop onions and garlic very finely. Fry in a deep frying pan until the onions are transparent in butter.
Pour the washed mussels in the shell into the pan, add salt, pepper, thyme, bay leaf, pour the wine and cream. Cover and shake. Cook for a few minutes or until all the mussels have opened, stir or shake periodically so that all the mussels are evenly coated with the sauce.
When the mussels are ready, put them in a separate bowl. Discard the bay leaf and thyme from the sauce, add the mustard and stir constantly with a whisk for 2 minutes.
Pour the mussels with sauce, sprinkle with chopped herbs and serve.
Mussels with cream are a very tasty, delicate, aromatic and hearty dish. Cooking is very simple and fast, these mussels are perfect for any side dish or as a dish with a glass of wine on their own. Cook for a romantic dinner or for a family dinner. Serve the mussels warm.