Preheat oven: 350 degrees. Dice chicken in bite size cubes. Marinate chicken in the Italian dressing and Old Bay seasoning. Saute until 3/4's cooked. Drain of excess juice and place in chaffing dish. Place peppers, onions, mushrooms and garlic on top of the chicken. Cover with homemade Tony N' Tina's marinara sauce (about 1 1/2 half quarts). Bake for about 30 minutes.