Preheat the oven to 350°F (175°C).
In a large skillet over medium heat, cook the ground beef until browned, breaking it apart with a spoon, about 5-7 minutes.
Add the diced onion and minced garlic to the skillet with the beef. Cook until the onion is softened, about 3-4 minutes.
Stir in the frozen mixed vegetables and cook for another 2 minutes until slightly tender.
In a large bowl, combine the condensed cream of mushroom soup, milk, salt, black pepper, and dried Italian seasoning. Mix well.
Add the cooked ground beef mixture and cooked elbow macaroni to the soup mixture. Stir until everything is evenly combined.
Transfer the mixture into a greased 9×13 inch baking dish. Spread it out evenly.
Sprinkle the shredded cheddar cheese evenly over the top of the casserole.
Sprinkle the crushed potato chips evenly over the cheese layer.
Bake in the preheated oven for 30 minutes, or until the cheese is melted and bubbly and the topping is golden brown.
Remove from the oven and let the casserole rest for 5 minutes before serving.