Chicken Ratatouille

1 Tbsp vegetable oil
4 medium chicken breast halves, skinned, fat removed, boned, and cut into 1-inch pieces
2 zucchini, about 7 inches long, unpeeled, thinly sliced
1 small eggplant, peeled, cut into 1-inch cubes
1 medium onion, thinly sliced
1 medium green pepper, cut into 1-inch pieces
1/2 lb fresh mushrooms, sliced
1 can (16 oz) whole tomatoes, cut up
1 clove garlic, minced
1 1/2 tsp dried basil, crushed
1 Tbsp fresh parsley, minced
to taste black pepper