Bring a large pot of salted water to a boil over high heat. Add elbow macaroni and cook until al dente, about 7-8 minutes. Stir occasionally to prevent sticking. Once cooked, drain and set aside.

In a large skillet, heat 1 tablespoon of olive oil over medium-high heat. Add the diced steak, season with salt and pepper, and cook until browned, about 5-7 minutes. Remove from skillet and set aside.

In the same skillet, slightly reduce heat and add the diced bell peppers and onions. Sauté for about 4-5 minutes until softened and caramelized.

Lower heat to medium-low, pour in 1 cup of whole milk, and add garlic powder and onion powder. Stir until simmering, then gradually add 2 cups of shredded pepper jack cheese, stirring until melted and creamy.

Fold the cooked steak and drained elbow macaroni into the cheese sauce, mixing well. Cook for an additional 2-3 minutes to meld flavors.

Serve immediately in bowls, garnishing with chopped green onions on top.