Cook the pasta in well-salted boiling water until just al dente. Reserve 1/2 cup pasta water, then drain and set aside.
Sear the beef: Heat 1 tbsp oil in a large skillet over high heat. Season beef with salt, pepper, and garlic powder. Spread and sear without stirring for 90 seconds, then remove to a plate.
Cook the vegetables: Reduce heat to medium, add remaining oil. Cook onions and peppers 6 to 7 minutes until softened. Add garlic and cook 1 minute more.
Make the sauce: Stir in flour and cook 1 minute. Gradually whisk in beef broth and milk. Add Worcestershire, onion powder, and smoked paprika. Simmer 3 to 4 minutes until slightly thickened.
Add the cheese: Remove from direct heat briefly. Stir in cream cheese until smooth. Add provolone and mozzarella in stages, stirring between each addition.
Combine: Fold in cooked pasta and seared beef. Toss to coat everything evenly. Adjust salt and pepper. Use reserved pasta water to loosen the sauce if needed.
