Gratin aux Truffes

The robust fragrance of the truffle permeates the contents of the sealed pot, forming a fragrant black layer in the middle of the creamy slivers of potato. The idea is that the aroma is released only when the lid is lifted. If you lack fresh truffles, preserved will do (whisk the juice into the cream). Or substitute a layer of black olives, pitted and chopped, and marinated in a teaspoonful of truffle oil. Either way, make sure everyone knows what they’re getting — the real thing or the cop