In a large saucepan, melt butter and add onions, bell pepper, celery, garlic and bay leaves and cook over high heat. Saute about 2 minutes, stirring frequently. Add the seasoning mix and continue cooking 5 minutes. Stir in the sausage and chicken broth. Cook 5 minutes more stirring frequently. Turn off heat. Add the cornbread, milk and egg. Spoon dressing into a greased baking dish. Bake at 350 until browns on top for about 40 minutes.