Lightly grease a shallow, heat-resistant, non-metallic baking dish and set aside.
In a medium-sized heat-resistant, non-metallic bowl heat butter in Microwave 30 seconds or until melted. Add bread crumbs, chopped onion and green pepper. Heat, uncovered, in Microwave 3 minutes or until onion and pepper are tender. Add mushrooms and crab meat. Toss to gently combine. Add clam juice and stir to combine.
Equally stuff the trout with the filling mixture. Secure the openings with string or toothpicks. Place stuffed fish in prepared baking dish. Heat, covered with clear plastic wrap, 10 minutes or until fish flakes easily with a fork. Let fish stand, covered, at room temperature 2 minutes to finish cooking.