In a large saucepan cook pasta in salted water according to package directions. Drain; set aside. Meanwhile, in a large skillet over high heat, heat olive oil until hot. Add onion, garlic and red pepper; cook, stirring constantly, until garlic is fragrant, about 30 seconds. Add mushrooms; reduce heat to medium; cook, stirring occasionally, until golden, about 5 minutes. Add tomatoes and continue to simmer uncovered, until slightly thickened, about 15 minutes. Stir in olives, anchovies, capers and salt; add reserved drained pasta. Simmer until pasta absorbs some of the sauce, about 3 minutes. Serve immediately with grated Parmesan cheese, if desired. Serves 6.