Preheat your oven to 350°F (175°C).
In a large skillet, brown the ground beef over medium heat. Once browned, drain any excess fat.
Add the chopped onion and minced garlic to the skillet with the ground beef. Sauté until the onion is translucent, about 3-4 minutes.
Stir in the diced tomatoes, tomato sauce, corn, uncooked elbow macaroni, beef broth, Italian seasoning, salt, and black pepper. Bring the mixture to a boil.
Reduce the heat and simmer for 10 minutes, stirring occasionally, until the macaroni is tender.
In a mixing bowl, combine the milk and ½ cup of shredded cheddar cheese.
Pour the meat and pasta mixture into a greased 9x13-inch baking dish. Pour the milk and cheese mixture evenly over the top.
Sprinkle the remaining cheddar cheese on top of the casserole.
Cover with aluminum foil and bake in the preheated oven for 25 minutes. Remove the foil and bake for an additional 15 minutes, or until the cheese is bubbly and golden.
Remove from the oven and let it cool for a few minutes before serving.