Bring a large pot of salted water to a boil. Add the shell pasta and cook until al dente, per package instructions. Drain and set aside.
Melt the butter in a large skillet over medium heat. Add minced garlic and cook until fragrant, about 1-2 minutes.
Season steak cubes with salt and pepper. Add them to the skillet in a single layer. Sear for 3-4 minutes, turning occasionally, until browned and cooked to your liking.
Add the cooked pasta to the skillet. Toss everything together so the pasta soaks up the garlic butter and coats the steak.
Sprinkle grated Parmesan over the mix. Stir until it melts into a creamy sauce. Add a splash of reserved pasta water if it’s too thick.
Remove from heat, sprinkle with fresh parsley, and serve hot.
Notes
Swap steak for chicken or tofu for a twist. Use gluten-free pasta for dietary needs. Add veggies like spinach or mushrooms for extra flavor!