Mix yogurt rosemary, salt and pepper and spread them over the chicken breasts.
Brucs casserole with olive oil. Add onion and cherry tomatoes and 1/2 cup of wine or stock to casserole dish. Transfer the seasoned breasts over the onion and tomatoes.
Bake in a preheated oven at 325°F FOR: a- 15 MINUTES for BONELESS BREASTS and 20 for breasts with bones.