1. Heat olive oil in a skillet over medium heat and brown the Italian sausage until crumbly, 5–7 minutes, then drain excess grease.

2. Transfer browned sausage to the crockpot and add diced onion, minced garlic, crushed tomatoes, Italian seasoning, red pepper flakes, and chicken broth. Stir to combine.

3. Cover and cook on low for 5–6 hours or on high for 3–4 hours until flavors meld.

4. About 30 minutes before serving, stir in heavy cream and cheese tortellini, then cover and cook until tortellini are tender.

5. Ten minutes before serving, add chopped spinach and stir until wilted. Season with salt and pepper to taste.

6. Ladle soup into bowls, garnish with grated Parmesan, and serve with crusty bread or garlic knots.