Boil a large pot of salted water and cook the cheese tortellini according to package instructions until al dente. Drain and set aside.
In a skillet over medium-high heat, combine 1 tablespoon of butter and olive oil. Add chopped sage and fry until crisp; remove and set aside.
In the same skillet, add remaining butter and sauté sliced mushrooms until golden brown, about 5 minutes. Stir in minced garlic for an additional minute.
Add drained tortellini to the skillet with mushrooms. Stir in parmesan cheese, allowing it to melt into a creamy sauce. Season with salt and pepper.
Gently fold in crispy sage before serving immediately.