Preheat to 400. Prepare a 2-quart casserole dish with cooking spray; set aside. To prepare filling, heat oil over medium heat. Add chicken, onions, and bell peppers. Cook until chicken is no longer pink and vegetables are tender. Stir in chili seasoning mix, corn, crushed tomatoes, and water. Reduce heat and simmer, uncovered, 10 minutes. Pour chicken mixture into prepared pan. Meanwhile, to prepare biscuit mixture, combine baking mix, cornmeal, and milk in a mixing bowl. Spoon biscuit dough in mounds around edge of casserole. Bake, uncovered, for 15 minutes or until biscuits are light brown. Top with Monterey Jack cheese. Bake, uncovered again, for 3 minutes more or until cheese has melted.