My mom is a home ec teacher (although she was a SAHM while I was growing up) so all our food was from scratch. One of the things she made was Mashed Potato Meat Pie.
Press hamburger into a sturdy pie pan (I use Pyrex, foil won't be able to hold the weight of the completed dish). The hamburger will shrink a lot, even the extra lean variety that I grind myself, so really spread it to the edges. Season with salt, pepper and garlic powder then bake until the hamburger "crust" is thoroughly cooked. Top the cooked crust with homemade mashed potatoes and then pile on the shredded extra sharp cheese (but be careful as this will run off the edges and onto the bottom of your oven if you don't put foil under the pan). I like to kind of make a lip around the edge with the potatoes so that the cheese stays in the middle. Put the pie under the broiler until the cheese melts and gets a little brown. Slice and enjoy