This classic French hors d’oeuvre could not be easier: Put firm, juicy radishes on a platter (cut larger ones in half) and serve with fine sea salt and butter, homemade or store-bought.
Homemade butter tastes sweeter and fresher than ordinary store-bought butter—and so does the buttermilk that’s left over. To make it, whirl 2 cups heavy cream (preferably not ultra-pasteurized) in a food processor until it separates into buttermilk and clumps of butter—they’ll look like fluffy scrambled eggs. Keep whirling until butter forms bigger clumps, about 3 minutes. Pour mixture into a strainer (set over a bowl if you want to keep the buttermilk) and let drain briefly. Squeeze butter to extract remaining buttermilk (it’s okay if a little is left). Put butter into a second bowl and stir in fine sea salt to taste, if you like.