Recipe for Grilled Swordfish with Cilantro Butter

32 ounces fresh swordfish fillets (4 fillets), center-cut
2 tablespoons olive oil
Cilantro Butter
1 bunch cilantro
1/2 cup unsalted butter
juice of 1 lime
salt and freshly ground pepper, to taste

Serves 4. Prepare a charcoal fire. Swordfish is especially good cooked over mesquite charcoal, although other types of fuel are fine.
Lightly coat fillets with olive oil. When fire is ready, place fish on oiled grill and cook until just firm to the touch (about 4 minutes per side for thick fillets, less for thinner fillets: don't overcook). Serve immediately with Cilantro Butter.
Cilantro Butter: Wash cilantro thoroughly and remove thick stems. Combine with butter in food processor or blender with metal blade and mix for several seconds until light and fluffy. Blend in lime juice. Season with salt and cayenne pepper.