Cut fish steaks into 4 serving pieces. Place in ungreased square baking dish, 8 x 8 x 2 inches.
Mix oil, lemon juice, garlic and oregano; pour over fish. Cover and refrigerate, turning fish occasionally, 4 hours.
Remove fish from marinade; reserve marinade.
Broil or Grill
Broil: Place fish on rack in broiler pan; brush with marinade. Set oven control to broil and/or 550 degrees. Broil fish with tops 2-3 inches from heat until light brown, about 5 minutes. Turn carefully; brush with remaining marinade. Broil until fish flakes easily with fork, 5-8 minutes longer.
Grill: Either grease the grill or use a greased hinged-wire “cage”. Grill over medium high heat, 8-10 minutes each side. (Fish should flake easily, don’t overcook.)
Serve: Sprinkle with salt and pepper; garnish with lemon wedges.