Mussel Stew - cooking recipe

Ingredients

10 lb. mussels in the shells
1 large onion, chopped
1 Tbsp. butter
1/2 c. water or dry white wine
2 cloves garlic, crushed
1 Tbsp. chopped parsley
1 Tbsp. extra butter for thickening (optional)
pepper

Preparation

Scrub the mussels under running water with a hard-bristled brush, making sure to discard any mussel with an open shell.
Rinse in several waters to remove all the sand.
This is most important, as you will otherwise end up with a gritty stew.
Melt the chopped onion in the butter.
Add the mussels and all the other ingredients except the parsley and the extra butter.
No salt, please, for the mussels themselves are quite salty.
Put the saucepan on a fierce heat and cover with a glass plate so that you can see when the mussels open.
It takes only about 5 minutes.
When they are open, they are cooked.
Fish them out of the liquid and discard the empty top shell and the beard, keeping the shell to which the mussel is attached for serving.