In a large pot of boiling salted water, cook pasta according to package instructions; drain well and set aside.
Preheat the oven to 375 degrees. Cook the sausage to an internal temperature of 155 degrees using a thermometer. Turn over about halfway through cooking to brown on all sides. Once done set aside, cut into bite sized pieces before using.
Heat a nonstick pan over medium heat. Add the oil, shallots, garlic, mushrooms, and thyme. Saute until the mushrooms start to soften.
Stir in the broth and butter. Bring to a simmer until the sauce reduces and starts to thicken. Season with salt and pepper to taste. Remove from the heat and remove the thyme sprigs. Stir in the pecorino, sausage, and pasta.
Adjust the seasoning with salt and pepper if needed. Serve with bread. Garnish with pecorino, hazelnuts, and red pepper flakes.