Cook tortellini according to package directions, drain and set aside.
In a large skillet over medium-high heat, cook the Italian sausage, breaking it up with a wooden spoon, until browned and cooked through, about 8 minutes.
Remove sausage from the skillet and set aside, leaving about 1 tablespoon of drippings in the pan.
Add butter and minced garlic to the skillet and sauté for 1 minute until fragrant.
Pour in heavy cream and bring to a gentle simmer, then reduce heat and stir in Parmesan cheese until melted and smooth.
Add the cooked tortellini and sausage back to the skillet, tossing everything together until well coated.
Season with salt and pepper, garnish with fresh parsley, and serve immediately.