Bring a large pot of heavily salted water to a rolling boil. Add your 16 oz (450g) of refrigerated cheese tortellini to the water. Cook according to the package directions, which usually takes about 3 to 4 minutes. Drain the tortellini in a colander, but reserve about 1/4 cup (60ml) of the starchy pasta water.

Place a large skillet over medium-high heat and add 1 tbsp (15ml) of olive oil along with 1 tbsp (15g) of your unsalted butter. Add the 8 oz (225g) of sliced cremini mushrooms in a single even layer. Let them sit undisturbed for 2 to 3 minutes to develop a sear, then toss and cook for 2 more minutes. Remove and set aside.

Lower the heat to medium-low and add the remaining 3 tbsp (45g) of unsalted butter to the skillet. Once melted, toss in the 3 minced garlic cloves and sauté for 30 seconds. Slowly pour in the 1 cup (240ml) of heavy cream. Let simmer for 2 minutes. Turn heat to lowest setting and gradually whisk in 1 cup (100g) of grated parmesan cheese until smooth.

Transfer the cooked tortellini and the sautéed cremini mushrooms back into the skillet with the alfredo sauce. Toss until coated, using a splash of pasta water if the sauce is too thick. Serve in a rustic shallow bowl with a heavy garnish of extra grated parmesan cheese, freshly cracked black pepper, and finely chopped parsley.