Allow the mussels to cool, remove them from the pan and place them in a colander or sieve (strainer) and wash thoroughly (to remove the taste of the sauce). Split the shells and throw away the empty halves, then arrange the mussels in their shells on a plate. Cover with cling film and keep in the fridge until you are ready to use them.
Make a vinegar dressing (or, if you prefer, you can use a summer oil dressing). Finely chop a clove (or two) of garlic and sprinkle the pieces over the mussels. Spoon the vinaigrette over the mussels and eat them cold as a starter or an aperitif. They're tangy and delicious.