Oven Sausage Cassoulet

Name: Oven Sausage Cassoulet
Ingredients: 8 ounces dried Great Northern beans (1 1/4 cups); 4 cups cold water; 1 tablespoon canola oil or olive oil; 6 chicken thighs (about 2 1/4 pounds total), skinned; 2 medium carrots, thinly sliced; 1 medium onion, cut into thin wedges; 1 stalk celery, sliced; 2 cloves garlic, minced; 1 (14.5 ounce) can no-salt-added diced tomatoes, undrained; 6 ounces cooked light smoked sausage, cut into bite-size pieces; ½ teaspoon dried thyme, crushed; ¼ teaspoon salt; ⅛ teaspoon cayenne pepper (Optional)