Bring a large pot of salted water to a boil. Cook 1.5 cups of elbow macaroni until al dente, about 7-9 minutes, then drain and set aside.

In a skillet, heat oil over medium heat. Add 1 lb of ground beef and cook for 5-7 minutes until browned. Drain excess fat.

Add a chopped medium onion to the skillet and sauté for 2-3 minutes. Sprinkle in 1 tsp of garlic powder, 1 tsp of salt, and 0.5 tsp of black pepper. Add 1 cup each of frozen peas and carrots, cooking for 5 more minutes.

Reduce heat and stir in 1 can of cream of mushroom soup. Mix until well combined, then fold in the cooked elbow macaroni.

Preheat the oven to 375°F (190°C). Grease a baking dish, transfer the mixture, and spread evenly. Sprinkle 2 cups of shredded cheddar cheese on top.

Bake for 20 minutes until the cheese is bubbly and golden.

Let cool for a few minutes before serving.