1 medium-sized onion
Olive or salad oil
6 chicken cutlets
2 tablespoons flour
1 (14-1/2 to 16-ounce) can tomatoes
3 tablespoons balsamic vinegar* or red wine vinegar
1/2 teaspoon salt
Thickly slice mushrooms and zucchini; chop onion. In 12-inch skillet over medium-high heat, in 1 tablespoon hot olive oil cook zucchini until tender-crisp and lightly browned; remove to plate. It same skillet, in 1 more tablespoon hot oil, cook mushrooms until browned; remove to bowl.
Coat chicken with flour. In same skillet, in 2 tablespoons hot oil, cook chicken until lightly browned and juices run clear when pierced, about 10 minutes. Remove to bowl with mushrooms. in drippings over medium heat, cook onion until tender and browned. Stir in 1/2 cup water.
Return chicken mixture to skillet; add tomatoes, vinegar and salt; heat to boiling. Reduce heat to low; simmer, uncovered, 5 minutes. Add zucchini; heat.
Makes 6 servings.
* Balsamic vinegar, an aged vinegar, is less acidic, more aromatic that other vinegars. If using red wine vinegar, stir in 1/2 teaspoon sugar or to taste.