Slow Cooker Minestrone

Ingredients

• 6 cups vegetable broth
• 1 (28 ounce) can crushed tomatoes
• 1 (15 ounce) can kidney beans, drained
• 1 large onion, chopped
• 2 ribs celery, diced
• 2 large carrots, diced
• 1 cup green beans
• 1 small zucchini
• 3 cloves garlic, minced
• 1 tablespoon minced fresh parsley
• 1 1/2 teaspoons dried oregano
• 1 teaspoon salt
• 3/4 teaspoon dried thyme
• 1/4 teaspoon freshly ground black pepper
• 1/2 cup elbow macaroni
• 4 cups chopped fresh spinach
• 1/4 cup finely grated Parmesan cheese, or more to taste