I'm using the recipe from my Hotdish Heaven cookbook, which is a collection of traditional recipes.
What you need is:
1 box instant mashed potatoes, pre-cooked (or if you prefer to mash them yourself, you will need about 3 cups)
1 pound ground beef
Frozen mixed veggies
One onion, chopped
Garlic, minced (I didn't have any)
1 tsp. thyme (I have, sadly, run out of thyme)
Mix it all together, put in a casserole dish, and bake at 375 for 20-30 minutes. Fairly easy and you have some excellent comfort food.