Preheat oven to 400 degrees F.
In a large skillet, saute zucchini and tomatoes in olive oil over medium heat for 5 minutes. Remove skillet from heat and stir in vinegar and scallions. Sprinkle with pepper.
Arrange fish steaks in one layer in a medium oiled baking dish. Pour tomato and zucchini mixture over fish. Bake for 15 minutes or until fish is done.
Recipe provided by Low Cholesterol Olive Oil Cookbook