Preheat oven to 350. Spray a 8-inch casserole dish with cooking oil. Cook macaroni according to box. Lay cheese packet aside. Cut the cheese slices into pieces and set aside.
In a skillet over medium low heat cook the ground beef till no longer pink. Add two teaspoons of the sun-dried tomatoes and the two pop & cook sauteed glazed onions. Stir together. Cook on low until onions are thawed, then stir again. season with salt and pepper to taste.
Add the milk to a sauce pan and heat on medium until it comes to a boil. Whisk in the cheese packet. Add the cut up cheese. Stir until melted. Take off heat.
Add the meat to prepared dish. Drain the pasta and add to meat. Stir together.
Pour half of the cheese sauce over the meat mixture and stir. Pour the rest of cheese sauce over the top of meat mixture, do not stir.
Bake for 15 minutes. Slice the tomato and layer over the top. Season with salt and pepper. Bake another 10 minutes