Bring a large pot of salted water to a boil and cook the cheese tortellini according to package directions; drain and set aside.
Meanwhile, melt the butter in a large skillet over medium heat.
Add the minced garlic and cook, stirring, until fragrant, about 1 minute.
Sprinkle in the flour and stir constantly until it forms a paste and smells slightly nutty, about 1 minute.
Slowly whisk in the heavy cream; the mixture may appear thick at first but will smooth out. Add the salt and grated Parmesan and simmer until the sauce thickens, about 5 minutes.
Stir the thinly sliced spinach and sun-dried tomatoes into the sauce and cook just until the spinach wilts.
Add the drained tortellini to the skillet and gently toss to coat evenly with the Parmesan cream sauce. Serve immediately.
Notes
Use pre-shredded Parmesan for convenience.
Reserve a little pasta cooking water to loosen the sauce if needed.
Thinly slice sun-dried tomatoes for even distribution.