Steam for a few minutes until soft. Extinguish with wine and reduce by 1/3. Add whipped cream. Bind (assemble) sauce with remaining ice-cold butter pieces and season. Roast mussels in a little hot clarified butter for about five minutes, then season. Divide the sauce evenly among plates and place the mussels inside. Finally, garnish each unit with shaved truffle.
Tip: Instead of clarified butter, you can also use butter in most cases.