In a large skillet or pan, heat the olive oil over medium heat.
Add the Italian sausage to the pan, breaking it apart with a wooden spoon. Cook for about 5-7 minutes until browned and cooked through. Remove excess grease if necessary.
To the same pan, add the diced onion and bell pepper. Sauté for about 5 minutes until the onion is translucent and the peppers have softened.
Stir in the minced garlic and cook for an additional 1 minute, until fragrant.
Pour in the can of diced tomatoes (including the juice), chicken broth, dried oregano, basil, red pepper flakes, and season with salt and pepper. Bring the mixture to a simmer.
Once simmering, add the tortellini to the pan. Stir to combine, and cover the skillet. Cook for 8-10 minutes until the tortellini are cooked through and tender.
Gently fold in the baby spinach and cook for another 1-2 minutes until wilted.
If desired, sprinkle with grated Parmesan cheese before serving.
Notes
Serve directly from the pan for a rustic look, garnished with fresh basil and extra Parmesan.