Prepare a medium sized frying pan with oil.
Clean and chop the onion and celery, toss into the medium sized frying pan, saute until they are slightly brown.
If adding fresh mushrooms to the dish, clean and chop and add to the frying pan with the other vegetables.
In a couple sauce pans, cook the green beans and corn until done, do the same with the carrots, drain and add to the sauteed vegetables.
While the vegetables are cooking preheat the oven to 350° F.
In a 1 cup measuring cup, add the plant milk, soy sauce, salt, pepper, and cornstarch, then blend well.
Then add to the fry pan with all the vegetables, cook over medium heat until the sauce thickens.
Add the cooked rice, stir, and then pour the mix into a 2 1/2 Quart baking dish.
Lay the frozen tater tots in a single layer on top.
Spread or sprinkle the vegan cheese over the top of the tater tot's.
Cover the dish and place into the oven, bake for 45 minutes.
Uncover the dish and continue baking for another 5 to 10 minutes.
Once the hotdish is done, remove from the oven and let it set for about 10 minutes before serving.
Serve with your favorite vegetables, and enjoy!
