Preheat grill to medium heat. On a floured surface, Roll pizza dough on both sides, and stretch round into an 8-inch square. Place dough on grill over medium heat, and cook 1 ½ to 2 minutes per side, using tongs to turn.
Cut catfish fillets into strips, and season with blackening spices. Grill catfish strips, and hold warm in a 200° F oven or warming drawer.
In a bowl, toss together red and green bell peppers, olives and green onions. Set mixture aside. In another bowl, whisk together hoisin sauce, soy sauce, pineapple juice, vinegar and garlic. Toss vegetable mixture with ⅓ cup hoisin dressing.
Lay grilled pizza dough on flat work surface. Top with ½ cup vegetable mixture, 2 tablespoons dressing and 2 hot catfish strips. Roll sandwiches, and serve.