Thoroughly clean the mussels and rinse well. Remove any opened or damaged mussels.
Put the mussels in a saucepan and fill them with water so that they are completely covered. Add the stock cube. Cook the mussels until they are all open. Possibly still closed mussels sort out and throw away.
Serve the mussels with a mussel sauce or the broth.
This recipe can also be used to cook mussels and then use them in other dishes.