Route 66's Famous Fried Onion burger

[KlausSchadenfreude]

In El Reno, a small industrial town just west of Oklahoma City on
Oklahoma's portion of Route 66, Sid's Diner is hopping during lunch.
With the sharp smell of crisping onions and burger grease in the air,
most of the diners in the joint are munching down on a sandwich that
was born out of poverty but made famous by love.

Adam, the second-generation owner at Sid's Diner, taking over from his
father Marty Hall, is working the flat iron grill. He presses the
patty of beef mince made juicy with a mess of sweet onion slivers onto
the searing heat. As meat cooks to a nice crispy crust, he flips the
burger onion-side down, letting the grease and the grill cast the
magic of caramelisation.

Marty figures he's flipped five million burgers in his life. He's made
a living out of cooking the famous Oklahoma fried onion burger, a thin
patty of beef filled with grilled, caramelised onion served on a
flat-grill crispy bun. He's even designed his own "onion burger
spatula", handmade from a masonry trowel.

Read more:
https://www.bbc.com/travel/article/20230626-the-depression-burger-of-route-66

Here's a photo of this big hot juicy bastard:
https://ychef.files.bbci.co.uk/1024x1280/p0fw57kk.webp