Bring this to a boil and strain the garlic slices. Repeat 3 times, discarding the milk and replacing it with a fresh 1/4 cup of milk each time. When you are done, you will have boiled the garlic slices in 4 changes of milk. This is kinda a pain, but it is essential. The milk leaches the bitterness from the garlic. It definitely takes 4 times, and without this step, your garlic chips will be terribly bitter.