First of all, you have to brown the beef. You can use grill to brown the beef or you can simply keep it in an oven for a while. Then, cut the onions and garlic in a bowl. Add salt and pepper according to your taste in the bowl and mix the browned beef.
You can choose any vegetable (carrots, peas, beans or corn etc) to include in you dish. You can add multiple vegetables, but it will be better for you to stick to only one vegetable. However, if you still want to add more than one vegetable, mushrooms will be a good option as it complements well with almost all the other vegetables.
It is very important for you to choose your sauce properly. Cream of celery and cream of mushroom are considered as the finest sauces to make tater tot Hotdish. However, if you like any other sauce, you can use it as well. But, make sure that it will make you dish tastier rather than affecting its taste in a bad way.
Now, take a large cake pan and place the beef, sauce and vegetables in it. Mix all the ingredients well with each other with your hand.
Cut the potatoes in layers and place the pieces on the top of your beef-veggie-sauce mixture.
Then, preheat your oven to 350 degrees Fahrenheit and place the cake pan in it for around an hour. It is extremely important for you to keep an eye on your dish while it is in the oven so that it may not get overheated.
Take it pan out of the oven and keep it aside for a while. Let it cool down before serving.