01 - Bring a large pot of salted water to a rolling boil. Cook the pasta according to package directions until al dente. Reserve 1/2 cup of the pasta cooking water, then drain the pasta.
02 - While the pasta is cooking, heat the butter and olive oil in a large skillet over medium heat. Add the minced shallot and cook for 1 to 2 minutes, until softened and translucent.
03 - Add the minced garlic to the skillet and cook for 30 seconds until fragrant. Stir in the finely chopped mushrooms. Cook, stirring occasionally, for 8 to 10 minutes, or until the mushrooms have released their moisture and it has evaporated. The mixture should be deeply browned and achieve a paste-like consistency.
04 - Deglaze the skillet with the dry white wine, scraping up any browned bits from the bottom of the pan. Cook for 2 to 3 minutes, until the wine is almost completely absorbed. Stir in the fresh thyme, chopped parsley, salt, and freshly ground black pepper. Remove the skillet from the heat.
05 - Add the drained pasta to the skillet containing the mushroom duxelles. Toss thoroughly to ensure the pasta is evenly coated. Add reserved pasta water, a tablespoon at a time, as needed to create a silky, emulsified sauce.
06 - Stir in the grated Parmigiano-Reggiano until melted and well combined. Taste and adjust the seasoning as necessary.
07 - Plate the pasta immediately. Finish by misting or drizzling with truffle oil. Garnish with additional chopped parsley and extra grated cheese, if desired. Serve promptly.