Cook the fettuccine pasta according to package instructions until al dente. Drain and set aside, reserving 1/2 cup of pasta water.
In a large skillet, heat the olive oil over medium-high heat. Season the sliced steak with garlic powder, salt, and pepper. Add the steak to the skillet and cook for about 3-4 minutes, or until browned and cooked to your desired doneness. Remove the steak from the skillet and set aside.
In the same skillet, reduce the heat to medium and add the heavy cream. Stir in the grated Parmesan cheese until melted and smooth.
Add the cherry tomatoes and fresh spinach to the skillet, cooking until the spinach wilts, about 2-3 minutes.
Return the cooked steak to the skillet and toss everything together. If the sauce is too thick, add a little reserved pasta water until you reach your desired consistency.
Add the cooked fettuccine to the skillet and toss to combine, ensuring the pasta is well coated in the creamy sauce.
Serve immediately, garnished with fresh parsley.
Notes
For a lighter version, substitute half-and-half for heavy cream and reduce the amount of cheese.
Add sautéed mushrooms or bell peppers for extra flavor and nutrition.