Sauté the aromatics (optional but recommended): In a skillet, warm a drizzle of olive oil over medium heat. Add onion, carrots, and celery with a pinch of salt. Cook 5–6 minutes until softened. Stir in garlic for 30 seconds. Transfer to your slow cooker.

Brown the sausage: In the same skillet, cook sausage, breaking it up with a spoon, until browned and no longer pink. Drain excess fat, then add to the slow cooker. For vegetarian, skip this step and add an extra cup of beans or mushrooms.

Build the base: Add crushed tomatoes, broth, tomato paste, Italian seasoning, dried basil, red pepper flakes, bay leaf, and a few grinds of black pepper. Stir to combine.

Slow cook: Cover and cook on Low for 5–6 hours or on High for 2.5–3 hours, until the vegetables are very tender and flavors have melded.

Add tortellini: Stir in tortellini, re-cover, and cook on High for 15–25 minutes, until the pasta is tender but not mushy. Check at 15 minutes.

Finish with greens and cream: Stir in spinach and let it wilt, 2–3 minutes. Add cream and adjust salt and pepper. Remove the bay leaf.

Serve: Ladle into bowls and top with grated Parmesan and fresh herbs. Add a drizzle of olive oil if you like.