Bake a batch of these puffs using all three fillings. One is never enough.
4 tablespoons chilled unsalted butter, cut into ½-inch pieces
½ cup freshly grated Parmesan cheese
½ cup all-purpose flour
Dash of cayenne pepper
Dash of salt
24 fillings (select one or use a variety): pimiento-stuffed green Spanish olives, bottled cocktail onions, or dates
Combine the butter, cheese, flour, cayenne pepper, and salt, in a food processor; process until the mixture begins to come together. Remove and shape into a ball.
If using olives or onions, drain them well and pat dry with paper towels. If using dates, cut them in half crosswise and press into balls.
Pinch off about 1 teaspoon of the dough, flatten slightly, wrap around the filling, and roll the ball between your hands. Place on an ungreased or parchment-lined baking sheet. Repeat to form the remaining puffs.
Lightly cover the baking sheet with plastic wrap and refrigerate for about 1 hour.
Preheat the oven to 350° F. Put the chilled baking sheet in the oven and bake the puffs for about 15 minutes, or until lightly browned.
Serve warm or transfer to a wire rack and serve at room temperature.
The puffs can be rolled up to 1 day in advance; cover and refrigerate. Bake just before serving. The completed puffs can be made up to 2 days in advance; cover and refrigerate. Serve at room temperature or reheat in a 350° F oven for about 5 minutes, or until warmed through.