Preheat the Oven: Preheat your oven to 350°F (175°C) to prepare it for baking.
Brown the Beef: In a large skillet, heat some oil on medium heat. Add the ground beef and chopped onions. Cook until the beef is browned and the onions are translucent. Drain any excess fat.
Add the Veggies: Stir in the frozen mixed vegetables. This gives the hotdish a lovely pop of color and nutrition!
Combine the Sauce: Pour in the cream of mushroom soup and milk. Mix everything together until well-blended.
Mix in Pasta: Add the cooked pasta to the beef mixture, stirring well to combine all the ingredients. Season with salt and pepper to taste.
Transfer to Baking Dish: Pour the mixture into a greased 9x13 inch baking dish, spreading it evenly.
Top with Cheese and Breadcrumbs: Sprinkle the shredded cheddar cheese over the top, followed by breadcrumbs if you choose for an extra texture.
Bake: Place the dish in the preheated oven and bake for 25-30 minutes, or until bubbly and golden on top.
Cool and Serve: Let the hotdish cool for a few minutes before serving. Enjoy with your loved ones!