Chicken Cacciatore With Crisp Polenta

Name: Chicken Cacciatore With Crisp Polenta
Ingredients: 3 tablespoons olive oil; 8 skinless chicken thighs (about 3 pounds total); Coarse salt and ground pepper; 10 ounces white mushrooms, trimmed and quartered; 1/4 cup all-purpose flour; 1 can (28 ounces) whole tomatoes in juice, broken up with a spoon; 1 cup dry white wine, such as Sauvignon Blanc; 2 medium onions, each cut into 8 wedges; 4 garlic cloves, sliced; 1/3 cup pitted green olives, halved; 1 tube (16 ounces) plain prepared polenta, sliced into 12 rounds