In a large oven-safe pan with a lid, heat oil over medium heat. Add onion, carrot, celery, garlic, Italian seasoning, crushed fennel seed, red pepper flakes, salt, and pepper. Cook for 8 minutes, stirring occasionally, until the veggies soften; then push to the edge of the pan.
Increase heat to high. Place sausage in the center of the pan in a single layer. Let it sear briefly, then use a wooden spoon to break it up and stir until browned. Drain off excess grease if needed.
Add tomato paste, stirring constantly for 1 minute. Pour in the chicken broth to deglaze the pan, scraping up any browned bits. Continue cooking until the broth has mostly evaporated.
Stir in crushed tomatoes. Add tortellini, pressing them below the surface as much as possible. Reduce heat to low, cover, and simmer for 5 minutes. If you don’t have a fitted lid, just cover the pan with a sheet pan.
Stir in spinach and heavy cream. Adjust seasoning as needed. Smooth the top to create an even surface, ensuring the tortellini are well submerged. Top evenly with mozzarella and Parmesan cheese. Place pan in the oven and bake for 10 minutes, until the cheese is bubbly and golden.
Optionally, garnish with parsley. Serve hot with hearty buttered bread for dunking. Best enjoyed right out of the oven.
Video
Notes
Note 1: Choose between sweet or spicy Italian sausage based on personal preference. If using sausage links, remove the casings before cooking.Note 2: The recipe’s timing and liquid quantities are counting on the use of fresh, refrigerated tortellini that cooks in boiling water within 4–5 minutes, as indicated on the package.Storage: Baked Tortellini is best enjoyed hot right out of the oven, as it will absorb the sauce and change texture if left to sit. Store leftovers in an airtight container in the fridge for up to 3 days. When reheating, add a splash of broth to restore the sauce’s consistency.