1Preheat your oven to 375°F (190°C).
Peel and slice the 4 medium potatoes into thin rounds.
Finely chop the medium onion.
In a large pot, bring water to a boil and cook the potato slices for about 10 minutes, or until they are just tender. Drain and set aside.
In a large mixing bowl, combine the cooked potatoes, chopped onion, 1 cup of mixed vegetables, and 1 cup of shredded cheese. Mix well.
Transfer the mixture into a greased baking dish.
Sprinkle 1 cup of bread crumbs evenly over the top of the casserole.
Bake in the preheated oven for 25-30 minutes, or until the top is golden brown and the cheese is bubbly.
Remove from the oven and let it cool for a few minutes before serving.
Enjoy your Cheesy Potato Casserole!