Set a large skillet over medium-high heat. Add the sausage and start to break apart into small crumbles as it sizzles. Cook for 4-5 minutes, until the sausage is well-browned. If there is a lot of rendered fat, dab or drain some of it off.
8 ounces crumbed Italian sausage
Add minced garlic and tomato paste to the sausage. Stir well and cook for 30-60 seconds, just until fragrant.
2-3 cloves garlic, 2 Tablespoons tomato paste
Add tomato sauce and broth. Stir well until the tomato paste is dissolved. The sauce mixture should be mostly smooth around the sausage crumbles.
1 (15 ounce) can tomato sauce, 1/2 cup low-sodium chicken broth
Stir in the cream or half and half, then sample and season with salt and pepper to taste. (It may not need much or any; it depends mainly on how generously-seasoned your sausage is.)
1/2 cup heavy cream, kosher salt and black pepper
Stir in the uncooked tortellini. Reduce heat to medium-low, cover the pan, and cook for 5 minutes. Uncover the pan and test a tortellini from the middle; if it is not tender, re-cover and cook another minute or two.
18-20 ounces refrigerated tortellini
When the tortellini is cooked through, remove the lid and stir in the spinach. Let it wilt for 1-2 minutes, then top with Parmesan and serve.
3 cups fresh baby spinach, Parmesan cheese