sausage and lentil soup

Ingredients

• 1 pound hot italian sausage
• 1 large onion, chopped
• 1 - stalk celery, chopped
• 2 large carrots, chopped
• 1 small zucchini, chopped
• 8 cups chicken broth
• 2 cans diced tomatoes, undrained (14-1/2 oz cans)
• 2 cloves garlic, minced
• 1 teaspoon salt
• 2 cups dry green lentils, rinsed
• 3/4 teaspoon black pepper
• 1/2 teaspoon red pepper flakes
• 1/2 teaspoon dried oregano
• 1/2 teaspoon dried thyme
• 1/2 teaspoon fennel seeds
• 1 - bay leaf
• 1/2 cup parmesan cheese, freshly grated