Fill a large pot with water, add a generous amount of salt, and bring to a rolling boil. Add the bowtie pasta and cook according to package directions, about 8 to 10 minutes. Drain, reserving 1/2 cup of the pasta water, and set the pasta aside.

While the water heats, slice the beef against the grain into thin strips and season generously with salt and pepper.

Heat a large 12-inch skillet over medium-high heat with the tablespoon of oil. Sear the beef in a single layer, working in batches if needed, for 1 to 2 minutes per side until browned. Remove the beef and set aside, leaving the fond in the pan.

Reduce the heat to medium. Add the butter to the skillet. Once melted, add the minced garlic and red pepper flakes. Stir constantly for about 30 seconds, being careful not to burn the garlic.

Pour in the heavy cream and let it simmer for 1 minute. Gradually whisk in the reserved pasta water to help emulsify the sauce.

Stir in the grated Parmesan cheese until melted and smooth.

Add the cooked pasta and seared beef back into the skillet. Toss gently to combine, adding more pasta water if the sauce is too thick. Cook for 1 minute to let the flavors meld.

Remove from heat. Stir in half of the fresh parsley. Taste and adjust seasoning with salt or pepper. Serve immediately topped with remaining parsley and extra Parmesan.