Chicken Braised with Garlic & Vegetables

2 tbsp butter (I use margarine)
2 tbsp extra-virgin olive oil
3 whole chicken breasts (bone in) with skin -- split & patted dry (I use debonned chicken thighs. I love them because they are so flavorful)
1 large onion -- chopped coarsely
6 small red potatoes -- scrubbed & halved (I use whatever potato I have available)
3 carrots -- scrubbed, peeled & cut 2" pc
2 lg heads unpeeled garlic -- cloves separated (I use 7 garlic cloves, peeled & thinly sliced)
1 tbsp herbes de provence -- OR
1/3 cup fresh parsley, sage, rosemary, thyme -- minced
fresh herbs -- for garnish
salt
ground black pepper
Toasted bread -- for accompaniment

In a large saute pan, heat butter and olive oil over medium-high heat. Brown chicken on both sides; about 10 minutes. Transfer to a platter. Add onions, potatoes and carrots and saute, stirring, over medium-high heat for several minutes to brown lightly. Remove from heat. Arrange chicken, skin side up, over vegetables. Scatter garlic cloves over all. Sprinkle with herbs, salt and pepper (Chicken can be prepared to this point several hours ahead & refrigerated. Bring to room temp before cooking). Cover skillet tightly, place over very low heat, and cook for 50 minutes, occasionally shaking the pan while holding the lid tightly. Dish is done when chicken and onions are fork-tender (chicken should fall apart when touched). To serve, distribute among heated serving plates. Spoon juices over all and garnish with fresh herbs. Serve with crusty bread.