Preheat oven to 425. Line a baking sheet with foil; set aside. In a saucepan, cook mushrooms, onions, and bell peppers. Cook until tender. Add diced tomatoes, tomato sauce, sugar, and Italian seasoning. Cover and simmer for ten minutes, stirring occasionally. Place chicken patties on baking sheet. Bake ten minutes. Spoon two tablespoon tomato mixture over each patty. Top each with cheese half. Bake two minutes more, or until cheese has melted. Toss linguine with half the remaining tomato mixture. Place tossed pasta on serving plate. Top with remaining sauce and chicken patties.