Set mixture aside. DIRECTIONS. Grill catfish strips, and hold warm in a 200°F oven or warming drawer. Sprinkle lemon juice on both sides of fish. In another bowl, whisk together hoisin sauce, soy sauce, pineapple juice, vinegar and garlic. CUT catfish fillets into strips and season with blackening spices. Combine first 4 ingredients; rub the seasoning on catfish. Mix up the following ingredients (double if you're grilling two catfish): 1 tablespoon melted butter; 1 tablespoon lemon juice; Salt and pepper Seasoning the inside and the outside of the catfish is meant to both flavor the meat and keep it moist while it grills. For whole grilled catfish, seasoning plays more than one role. Grill, covered with grill lid, over medium hot coals (350-400°F) 5 minutes on each side until fish flakes easy with a fork. IN A BOWL, toss together red and green bell peppers, olives and green onions.