Chicken with Provencal Vegetables

large zucchini (10 ounces), sliced 1/8 inch thick on the diagonal

small tomatoes (6 ounces each), sliced 1/2 inch thick

large onion (10 ounces), sliced 1/8 inch thick

olive oil, divided

Coarse salt

small potatoes, sliced 1/4 inch thick

bone-in, skin-on chicken breast halves (2 1/2 pounds total), ribs removed