1. Bring a large pot of salted water to a boil. Add the bowtie pasta and cook according to package instructions until al dente, usually about 10-12 minutes. Drain and set aside, reserving about 1/2 cup of pasta water.
2. While the pasta cooks, heat a large skillet over medium-high heat. Add the ground beef, breaking it apart with a wooden spoon, and cook until browned and cooked through, about 6-8 minutes. Season with salt and pepper. If using sliced sirloin, cook for 3-4 minutes per side until just browned. Transfer beef to a plate and set aside.
3. Reduce heat to medium and add the butter to the same skillet. Once melted and starting to foam, add the minced garlic and chopped onion. Stir frequently, cooking until fragrant and the onions turn translucent, about 3-4 minutes. Be careful not to burn the garlic—it should smell sweet and nutty, not bitter.
4. Pour in the beef broth and scrape up any browned bits from the bottom of the skillet. Let it simmer for 2-3 minutes to reduce slightly.
5. Add the cooked pasta back into the skillet along with the browned beef. Toss everything together gently, adding reserved pasta water a tablespoon at a time if the mixture feels dry.
6. Stir in the Parmesan cheese and fresh thyme. Adjust seasoning with additional salt, pepper, and crushed red pepper flakes if using.
7. Once everything is heated through and glossy with butter, remove from heat. Sprinkle with chopped parsley for a fresh pop of color and flavor.
8. Serve immediately with extra Parmesan on the side. Mama Lu always said, “A little extra cheese don’t hurt nobody.”

One thing Mama Lu taught me was to trust your senses—taste along the way, and add seasoning bit by bit. It’s how you make this dish your own.