Preheat oven to 350°F. Place garlic on small baking pan. Pour 1 tablespoon oil over; toss to coat. Bake until soft, about 20 minutes. Cool garlic. Press garlic between fingertips to release from peel. Transfer garlic to bowl. (Can be prepared 1 day ahead. Cover and refrigerate.) Using meat mallet or rolling pin, pound chicken between sheets of plastic wrap to thickness of 1/2 inch. Coat chicken with flour; shake off excess. Heat remaining 2 tablespoons oil in heavy large skillet over medium-high heat. Add chicken and saute until cooked through, about 3 minutes per side. Transfer chicken to plates. Tent with foil to keep warm. Add mushrooms to skillet and saute 4 minutes. Add wine to skillet and boil until liquid is reduced by half, about 4 minutes. Add tomatoes, spinach, rosemary and roasted garlic and saute until spinach wilts, about 3 minutes. Add butter and mix just until melted. Spoon mixture over chicken and serve. Serves 4. CHIC 106