Place breadcrumbs in a mixing bowl. Set the oven to 375ºF. Bring the milk to a boil, then stir in the butter, salt and peppers and pour the mixture over the breadcrumbs. Add the garlic and Gruyere and return to the pan. Stir over moderate heat until cheese melts. Beat in the egg yolks. Cool the mixture slightly, then stiffly whip the egg whites and fold them into the mixture. Pour into a buttered pie tin (not more than three-quarters full) a bake for about 40 minutes.