In a Dutch oven, cook and crumble sausage over medium heat until no longer pink, 5-7 minutes; drain., Stir in lentils, beans, broth and water; bring to a boil. Reduce heat; simmer, covered, until lentils are tender, about 30 minutes. Stir in tomatoes; heat through., Remove from heat; stir in spinach until wilted. If desired, serve with goat cheese.