Cook green beans according to package directions, omitting salt and fat. Set aside, and keep warm.
Coat a nonstick skillet with cooking spray; add oil. Place over medium-high heat until hot. Add onion, green pepper, and garlic; saute 4 minutes. Stir in tomato, Italian seasoning, and salt. Cook until thoroughly heated, stirring often. Combine green beans and tomato mixture; toss lightly. Sprinkle with Parmesan cheese.