Sausage and Lentil Cassoulet

Name: Sausage and Lentil Cassoulet
Ingredients: * 4 piece hickory smoked bacon; * bay leaf; * 1 yellow onion, whole; * 1 yellow onion, chopped; * 1 cup green lentil, dry; * 1 tablespoon olive oil; * 2 carrot, peeled and chopped; * 1 celery stalk, chopped; * 1/2 teaspoon cayenne pepper; * 2 large garlic clove, chopped; * 1 teaspoon fresh sage, chopped; * 1 teaspoon fresh thyme, chopped; * 6 ounce kielbasa or other smoked garlic sausage, cut on a diagonal; into thick slice; * 1 cup breadcrumb; * 3 tablespoon unsalted butter