Bring a large pot of generously salted water to a rolling boil. Cook bowtie pasta according to package directions until al dente. Reserve 1/2 cup pasta water, then drain pasta. Do not rinse.

Heat olive oil in a large 12-inch skillet over medium heat. Add diced onion and cook for 2-3 minutes until translucent. Add minced garlic and cook for another 30 seconds until fragrant.

Add the ground beef to the skillet. Break it apart with a spatula and cook until browned and internal temperature reaches 160°F (about 5-6 minutes). Drain any excess fat if needed.

Stir in beef broth, red pepper flakes (if using), salt, and black pepper. Let it simmer for 3-4 minutes until reduced to about 1/3 cup, scraping up browned bits from the bottom of the pan.

Add the cooked pasta to the skillet. Toss everything well to coat. Add a splash of reserved pasta water or drizzle with a little more olive oil if needed for moisture and gloss.

Plate the pasta, sprinkle with freshly grated Parmesan and chopped parsley. Add extra cracked black pepper to finish.