Cook the Pasta:
Bring a large pot of salted water to a boil. Cook the pasta according to package instructions until al dente. Drain and set aside.
Prepare the Steak and Shrimp:
Season the steak pieces and shrimp with salt and pepper.
In a large skillet over medium-high heat, heat 2 tbsp olive oil. Add the steak pieces and cook until browned and cooked to your desired level of doneness. Remove from skillet and set aside.
In the same skillet, melt 2 tbsp butter. Add the shrimp and cook until pink and opaque, about 2-3 minutes per side. Remove from skillet and set aside with the steak.
Make the Alfredo Sauce:
In the same skillet, melt 4 tbsp butter over medium heat. Add the minced garlic and sauté until fragrant, about 1 minute.
Pour in the heavy cream and bring to a simmer. Cook for 3-4 minutes, stirring occasionally.
Gradually whisk in the grated Parmesan cheese until the sauce is smooth and creamy. Season with salt, pepper, and nutmeg (if using).
Combine Everything:
Add the cooked pasta to the skillet with the Alfredo sauce, tossing to coat the pasta evenly.
Add the cooked steak and shrimp to the skillet, gently tossing to combine with the pasta and sauce.
Serve:
Garnish with freshly chopped parsley and additional grated Parmesan cheese.
Serve the Steak and Shrimp Alfredo Pasta hot, with garlic bread or a fresh salad on the side.