After the ground chuck beef and onion are browned and drained, add the four cans of veggies (mixed, corn, and green beans), two packs of gravy mix, 2 cups cold water. Stir well. Allow the mixture to cook until thick. If it doesn’t thicken, add about 1/4 cup instant potato flakes and it will thicken nicely. If your mixture is too thick (gooey and lumpy, add about 1/2 cup more water.)
Pour mixture into a casserole dish and top with mashed potatoes.
Top generously with grated cheese.
Place under broiler until the cheese melts and starts to turn a nice golden brown.