Melt butter in heavy large skillet over medium-low heat. Add mushrooms, garlic, rosemary and generous amount of pepper. Cook until mushrooms exude their juices, stirring occasionally, about 5 minutes. Add cream and simmer until sauce thickens slightly, about 3 minutes. Season with salt. Meanwhile, cook pasta in large pot of boiling salted water. Drain well. Add pasta and cheese to sauce and stir until cheese melts. Sprinkle with parsley and serve.