The first sandwich I have any real memory of is the fried pork tenderloins (not breaded) that my grandmother made. Grandma was a farmer's daughter and had worked through the depression as a cook in a small-town Iowa "diner." That woman could sling a pork tenderloin, and she swore by lard. Grandma was a character.
(She lived to be 99, and none of her children came within ten years of that. The lard never did get her, though a hospital-related infection finally did.)
Everything was cooked in lard
Praise the Lard!