Prepare rice mix according to package directions.
In a large skillet, cook the breakfast sausage until browned through, cutting it into small pieces with spatula as sausage cooks. Remove sausage.
Dice the vegetables. Add the onion, green pepper and mushrooms to the remaining grease, cooking until onions turn clear. Drain grease, add the rice and tomatoes. Stir.
Rub the trout inside and out with the seasonings. Stuff the trout with the rice and vegetable mixture. Cook in a preheated 325 F. oven about 35-40 minutes or until trout separates easily from bone with a fork.
Serves 4.