Season both sides of the steak with salt and pepper.
Place a large cast iron skillet over medium high heat with 1 tablespoon butter and 1 tablespoon oil. Once very hot, place the steak in and cook for 5 minutes on the first side. Flip over and transfer to the oven and cook for 5 minutes. Remove from the oven and let rest.
Add the remaining butter and oil to another large skillet and set over medium-high heat. Once hot, add the shallot and garlic and cook until softened, about 2 minutes. Stir in the mushrooms and cook, stirring often, until they’ve browned, about 8 minutes.
Cook the pasta according to package directions. Drain and set aside.
Add the cream, lower the heat and simmer until reduced and thickened, about 10 minutes. Stir in ¾ cup of the parmesan and the sun dried tomatoes. Stir in the cooked pasta and parsley and stir until evenly combined.
Slice the steak into thin slices on an angle and then add to the pasta. Stir until just combined. Serve with parsley and parmesan on top.