Black Lentil Stew with Sausage and Kale
1 (12 ounce) ring smoked garlic sausage, slic… 1 bay leaf 1 large carrot, cubed 1 large tomato, diced 1 pinch cayenne pepper, or to taste 1 rib celery, chopped 1 teaspoon salt, or more to taste 1 yellow onion, chopped 1 ½ cups black lentils 2 bunches lacinato (dinosaur) kale 2 tablespoons butter 2 tablespoons sour cream, or to taste 6 cups chicken broth freshly ground black pepper to taste