Slice the beef liver as thinly as you can; place slices on racks of dehydrator, sprinkle with garlic powder; dry for 12 -15 hr.
OR
Slice the beef liver as thinly as you can; place slices on several cookie sheets, sprinkle with garlic powder and dry in barely warm oven (usually takes 12 -14 hrs - keep testing)
When done, snap dried slices into pieces and store in a tightly closed plastic bag.
This recipe was sent to me my a colleague who has cats that love these treats. She/he advises they cost a fortune to buy but cats love them... so making them is a cheaper option.