Place the rack in the top third of the oven and preheat to broil.
In a small bowl, whisk together sour cream, cilantro, garlic, salt and pepper. Cover and refrigerate until ready to serve.
Prepare Mediterranean Spice Rub.
Place fish on a lightly greased broiler pan. Brush with melted butter. Sprinkle with the spice rub. Broil until fish flakes easily with a fork, about 8 to 10 minutes.
Transfer fish to a serving plate. Top each with a dollop of sour cream mixture. Garnish with lime wedges.
Mediterranean Spice Rub
In a small bowl, combine onion powder, garlic powder, coriander, cayenne and salt.
Contributed by Joyce Taylor MM2