- 1 1/2 sticks (3/4 cup) unsalted butter, softened
- 2 1/2 tablespoons whole-grain or coarse-grain mustard
- 3 tablespoons chopped fresh tarragon
- Blend all ingredients with salt and pepper to taste in a food processor until smooth. Chill butter, covered, until just firm but still malleable, about 30 minutes. Transfer butter to a sheet of wax paper and roll into a 6-inch log. Chill, wrapped in wax paper and then foil, until firm, about 1 hour.