Add the butter to a skillet over medium heat. Once it melts, add the garlic and sauté for about a minute, stirring constantly.
Add in the tomato paste, tomato sauce, cream, and Italian seasoning. Stir/whisk until it's nice and smooth.
Stir in the tortellini (no need to boil it first). Reduce the heat to medium-low and cover the pan and cook for 5 minutes.
If the tortellini is still a little firm, continue cooking it for another few minutes (stoves and pans vary). If needed, increase the heat a bit. If the sauce thickens/reduces too much (the pasta releases starch, thickening the sauce as it cooks), add another splash of cream or a little chicken/veg broth.
Season with salt & pepper as needed (I'm fairly generous with both).
Serve immediately with plenty of parmesan cheese grated over top.
