St. Peter’s Fish with Black Truffle Mousse, White Asparagus, and Mousseline

Fish and Mousse

• One 2.25- to 2.75-kilogram St. Peter’s fish (John Dory), skin removed
• 3 sea scallops

St. Peter’s fish, also known as John Dory, is a mild white fish; although it is not a true flatfish, it has two fillets per side, so one large fish will serve four. We puree the belly and the trim from its fillets for the mousse, a way to use all of the valuable fish.

This dish couldn’t be more traditional seeming, yet it would be impossible to cook so precisely without the technology o