Heat a large pot of water over high heat. When boiling, add the pasta and cook as per package directions, approximately 11 minutes, until al dente. When done, drain and set aside.
While the pasta is cooking, slice your steak into thin pieces. (Approximately 1/4 inch thick, 1/2 inch wide, and 2-3 inches long).
Heat a large skillet over medium heat. Add the vegetable oil and when hot, add the peppers and onions. Lightly season with salt and pepper. Cook until just translucent and beginning to soften, approximately 5 minutes. If you want soft vegetables, cook longer to your preference.
Remove the vegetables and set aside. Put the skillet back on the heat and add the steak. Sprinkle with salt and pepper. Cook until the meat is browned and cooked mostly through, approximately 3 minutes. This will vary based on the thickness of your steak and preferred doneness. Remove from the skillet and set aside.
By now your pasta should be done. Put the empty pasta pot back on the stove and heat over medium heat. Add the butter until melted and then whisk in the flour to make a roux. Cook the roux until the butter is just starting to turn a light brown.
Whisk in the milk to the roux mixture. Cook until the milk is heated through, approximately 3 minutes. Remove the pot from the heat.
Add the cream cheese and 4 oz of provolone to the milk. Stir the sauce off the heat until the cheese is melted. Add 1/4 tsp each of salt and black pepper. The sauce will be thicker at this point. Do not do this over heat as the heat will cause the cheese to break and separate. Season the sauce with more salt and pepper to taste.
Add the pasta, vegetables, and steak back into the pot with the cheese sauce. Toss to combine.
Pour the pasta mixture into a large 9x13 baking dish. Layer the remaining 8 oz of provolone on top of the pasta.
Bake until the mac and cheese is warmed throughout, approximately 20-30 minutes.
Remove from the oven and set aside to sit 5-10 minutes. Serve warm.
Notes
For a saucier mac and cheese, increase the milk to 3 cups and adjust seasoning accordingly. The sauce will be a little thin. You can also increase the butter and flour to 3 Tbsp each.For meat lovers, increase the steak to 1.5-2 pounds