Hearty Lentil and Sausage Soup

Name: Hearty Lentil and Sausage Soup
Ingredients: 2 Tablespoons olive oil; 1/2 Cup chopped carrots; 1/2 Cup chopped celery; 1/2 Cup chopped yellow onion; 2 Tablespoons finely chopped garlic; 1/2 Pound sweet or hot Italian sausage, casings removed; 1/2 Pound mushrooms; 1 Cup dried French or brown lentils, picked through and rinsed; 2 1/2 Cups beef broth; 2 1/2 mushroom or low-sodium chicken broth; 1 Cup chopped tomatoes, with their juice; 1 Cup dry red wine; 1 Pinch of red pepper flakes; 1/4 Pound baby spinach, thinly sliced; 1/2 Teaspoon salt; Black pepper; 1 Tablespoon chopped thyme; 6 Teaspoons grated Parmesan cheese, for garnish