Version 1:
Large slice of raw liver
Garlic powder

Sprinkle liver generously with garlic powder. Preheat oven to 450 degrees. Put liver on nonstick metal cookie sheet and bake 10 minutes, turn off oven and leave until cooled. Slice and freeze. Works great and is easy. You can turn liver over when you turn off oven if you want.

Version 2:
Raw liver
Egg with shell
Garlic powder
Uncooked oatmeal

Puree liver, egg, and generous amount of garlic powder in a food processor. Add oatmeal until it is the consistency of cookie dough. Grease and flour a glass baking pan and bake at 350 degrees for about 15 minutes. You really need to check on it occasionally as times can vary. Cool, slice, and freeze. This makes a nice dry but palatable cookie that I've never seen any dog refuse.