The first time I had shrimp and grits, I was sitting on a screened-in porch outside Charleston, with a breeze coming off the marsh and a glass of sweet tea sweating beside my plate. The shrimp were perfectly seasoned, the grits were creamy and rich, and I remember thinking, This is the kind of food ...

Back during the Great Depression, Oklahoma diners had to get creative — meat was expensive, but onions were cheap. So they smashed a handful of thin-sliced onions right into a burger patty and cooked it all together on a hot griddle. The result? Crispy, caramelized onions melted right into the beef,...