Cook the rigatoni in a large pot of boiling salted water according to the package instructions until al dente. Drain, reserving 1 cup of the pasta water.
In a large skillet, heat the olive oil over medium-high heat. Add the chopped shallots, sautéing until translucent.
Add the sliced mushrooms and cook until they release their moisture and it evaporates.
Stir in the butter and minced garlic, cooking until the butter is fully melted and the garlic is fragrant.
Pour in the heavy cream and season with Cheesoning, salt, and black pepper. Let it simmer for about 4 minutes.
Add the al dente rigatoni and grated Parmesan cheese to the skillet. Toss to combine, gradually adding the reserved pasta water as needed to achieve a creamy sauce consistency.
Continue cooking for an additional 3 minutes, ensuring the pasta is well-coated and heated through.
Serve hot, garnished with freshly chopped parsley and shavings or slices of Parmesan cheese.
