Here is a recipe I make with mashed potatoes. It's very good and can be fried and frozen and then reheated in the oven.
Left over potaotes (mashed) or boil some and mash
ground beef (browned, I cook mine with some garlic, chilli powder, cumin powder and corrainder powder along with salt)
1 cup cheddar cheese grated
1/4 cup of finely chopped fresh cilantro
1/4 cup of finely chopped fresh mint
1 jalapeno seeded and finely chopped (for more heat leave the seeds)
salt and black pepper to taste
Bread crumbs and eggs
oil to fry
In a bowl mix the potatoes, cheese, herbs and ground beef. Make them into small patties. Roll them first in bread crubms and then soak it in egg and fry them in oil. Serve with some ketchup or any sauce of your choice.