Boil penne in salted water according to package directions until al dente. Drain and set aside.
Sear the steak:
Heat olive oil in a large skillet over medium-high heat. Season steak slices with salt and pepper. Sear until browned on all sides but still tender inside. Remove from skillet and set aside.
In the same skillet, add garlic and bell peppers. Cook for 3–5 minutes until slightly tender but still vibrant.
Prepare the creamy sauce:
Reduce heat to medium. Pour in heavy cream, Parmesan, and Italian herbs. Stir until the cheese melts and sauce thickens slightly.
Combine everything:
Add the cooked penne and seared steak back into the skillet. Toss to coat evenly in the creamy sauce. Adjust seasoning with salt, pepper, or red pepper flakes.
Serve hot:
Garnish with extra Parmesan or fresh herbs if desired. Serve immediately.