Fill a large pot with water and bring to a boil. Add a generous amount of salt to the water, followed by the pasta. Cook for 7 to 9 minutes or until al dente, stirring occasionally. Drain into a colander and toss with a dash of olive oil. Set aside.
Place a large skillet over medium-high heat and sauté onions for about 3 minutes. Add garlic, thyme and mushrooms and continue to sauté for 4 to 5 minutes (if the mixture gets too dry add an additional tablespoon of water). Season with salt and pepper.
Deglaze the pan with the red wine and allow the liquid to reduce by ⅔.
Lower heat to medium-low and stir in cream and butter, if using.
Add pasta and stir together until well coated. Top with parmesan and fold together. Adjust seasonings.
Top each plate with extra Parmesan and cracked black pepper and serve.