Ok… I have tried this several times now with old frozen steak/regular fries and they have turned out great. Take these old pups and put in a sieve and rinse under hot running water. Drain well, sandwiching between some towels (cloth or paper). Put them in a food processor and pulse a few times until coarse to medium chop.
Sandwich the output between pieces of wax paper (or plastic) and form into a 3/8 inch thick rectangle, with something to press it down so it is about the size of your largest spatula.
Add using spatula to shallow fry in cast iron around 350°F. Season with salt and pepper and use the spatula to collect any loose pieces into the rect for a few minutes, then flip to fry the other side and season, continuing to fry for a couple of more minutes (again collect any loose pieces using spatula into the rect as needed; there should be few, if any at this point). Remove via spatula and drain on paper towel. Yum!