Sausage, Kale, and Cauliflower Soup

Name: Sausage, Kale, and Cauliflower Soup
Cuisine: Italian
Ingredients: 1 pound spicy Italian sausage, preferably bulk sausage, otherwise remove links from casings; 1 tablespoon olive oil; 1 medium onion, chopped; 3 cloves garlic, minced; pinch crushed red pepper flakes, optional; 4 cup low-sodium chicken broth; 1 medium cauliflower, cut into bite-sized florets; 1 bunch kale (about 10-12 stems), washed, destemmed, and cut into bite-sized strips; 1 cup heavy cream, or to taste; Salt and pepper to taste; Grated or shredded Parmesan cheese for serving