Radis Beurre Revisited

Crisp fresh radishes, good butter, and fleur de sel make the perfect trio for a French apéritif; it’s no wonder radis au beurre (which we always shorten to “radis beurre” at home as our own form of French slang) is a standard apéro all over France. We like to say that once you’ve eaten radis au beurre like this, though, you will never simply dip raw radishes into a bowl of butter again. It isn’t traditional, but so much more elegant: We dip the radishes in a quick butter mousse, made