Lemon Meringue Bombe with a Bitters Mousse and Black Currant Sauce

I learned the following dessert when I spent time in the kitchen with Michel Bras. He worked virtually like an alchemist. Beneath the underlying sweetness of the mousse there is strong and rewarding interaction among the bitters, the acid of the lemon, and the tart black currants. When they are combined, the sensation is dazzling—all the tastes explode together in the mouth.

Begin 3 to 4 days in advance