Preheat the oven to 180 C. If you have unopened shells, clean the shells under running water first to remove as much sand as possible. Open the shells by inserting a knife and cutting the muscle where it attaches to the flat part of the shell. Keep only the muscle (white part) and roe and put back in the shell.
Heat butter in a frying pan, add the minced shallots, cook for five minutes then add white wine and cook for two more minutes. Add this sauce to the shells and sprinkle with breadcrumbs.
Put the shells in preheated oven for 10 minutes then serve.