Cook pasta according to package directions. Reserve 1/2 cup pasta water. Drain pasta without rinsing
Meanwhile in a large skillet over high heat add 1 Tbsp olive oil and brown beef and onion, breaking up with a wooden spoon, about 2 minutes. Reduce to medium heat. Season with 1 tsp salt and 1/2 tsp black pepper. Stir in garlic, chili flakes, Worcestershire sauce, tomato paste, parsley and 1/2 cup pasta water. Simmer until meat is tender, about 8 to 10 minutes.
Toss in pasta and 1 cup of cheese. Top with remaining cheese and cover with lid. Garnish with additional parsley.