Skillet Tomatoes and Zucchini

2 T. butter or margarine
2 small zucchini, thinly sliced
1 med. onion, thinly sliced
½ tsp. garlic salt
½ tsp. basil
dash of pepper
1 c. grated mozzarella cheese
1 c. seasoned croutons

Melt butter in a large skillet. Add zucchini and onion. Cook over medium heat until crisp-tender. Gently stir in tomatoes, garlic salt, basil, and pepper. Cover; cook 3-5 minutes until tomatoes are tender. Remove from heat; sprinkle with cheese and croutons. Cover; let stand 2-3 minutes until cheese is melted.