Detroit.

From the body shop to the corner edge.

Gus Guerra opened Buddy's Rendezvous in Detroit in 1946. He baked his rectangular pies in repurposed blue-steel utility trays from the automotive factories — the same trays used to hold drill bits and small parts.

Two ideas emerged from those trays. First: a square corner has more crust per square inch than a round pie, so the corner slice became the prize. Second: pushing the cheese against the pan's vertical walls fries it into a crispy edge — the frico crown — that became Detroit's signature.

The sauce goes on top, ladled in racing stripes or splotches over the cheese after the pie comes out of the oven. The order matters: cheese first, sauce last, so the dairy fat doesn't make the underside soggy.