Preheat the oven to 350°F.
Boil water in medium sauce pan and cook the noodles until they are al dente (firm when you bite into them) drain and set aside.
While the noodles are boiling grill the onion and bell pepper over medium heat in oil until softened and the onion is translucent. Set aside.
In same skillet oven medium-high heat, heat oil. Add steak meat and season with salt and pepper. Cook until no longer pink. Remove steak meat to a large plate.
In medium size sauce pan melt the butter and cook the garlic over medium heat.
Stir in the flour, reduce the heat to low, and continue stirring for about 3 minutes. You will have a paste.
Add the milk and whisk. Continue cooking over medium heat while whisking for about 4-5 minutes.
Add 1/2 cup of the American cheese and 1/2 cup of the Jack cheese. Stir over low heat. Continue stirring until cheese is completely melted.
Add the noodles, grilled onion and bell pepper, and cooked beef. Stir until completely combined.
Transfer half the mixture to a casserole dish, I used a 9 x 11 dish I have, one of similar size will work. Add half of the cheese left over on top of the macaroni mixture. Then layer the rest of the macaroni mixture on top. Top with remaining cheeses.
Cover with foil and bake for 20 minutes. Remove the foil and bake for an additional 10 minutes. Serve and enjoy!