01 -
Preheat your oven to 350°F (175°C) and grease a 9×13-inch baking dish.
02 -
In a large skillet over medium heat, cook the ground beef and chopped onion until the meat is browned and the onion is soft. This should take about 6-8 minutes.
03 -
Drain any excess fat from the skillet. Stir in diced tomatoes, cream of mushroom soup, garlic powder, Italian seasoning, salt, and pepper. Mix well to combine.
04 -
Fold in the cooked pasta and stir gently until evenly coated.
05 -
Transfer the entire mixture to the prepared baking dish. Spread evenly.
06 -
Sprinkle the shredded cheddar cheese evenly over the top.
07 -
Bake in the preheated oven for 25-30 minutes until the cheese is melted and bubbly.
08 -
Let the casserole sit for 5 minutes before serving to allow it to set.