In a large pot, bring salted water to a boil. Add the tortellini and cook according to the package instructions until al dente (typically about 3-5 minutes). Drain and set aside.
In a large skillet over medium heat, melt the butter. Add the minced garlic and sauté for 1-2 minutes, until fragrant (be careful not to burn it).
Pour in the heavy cream and bring it to a gentle simmer, stirring occasionally.
Gradually whisk in the Parmesan cheese until the sauce is smooth and creamy. Add the nutmeg, and season with salt and pepper to taste.
Stir in the chopped spinach, allowing it to wilt into the sauce for 2-3 minutes. If using, add the sun-dried tomatoes at this point.
Gently fold in the cooked tortellini, ensuring they are well-coated in the creamy Alfredo sauce. Cook for an additional 2 minutes to warm everything through.
Taste and adjust seasoning if necessary.
Serve hot, garnished with fresh basil leaves for an aromatic finish.
Notes
Add sun-dried tomatoes for extra flavor if desired.