you gotta marinate them in your butt for at least two mornings, maybe an extra half morning if you want em really flat

It's probably beef/veal shank, these steaks curl in that shape if you don't cut the membrane enveloping the meat.

Also stop copying posts from reddit, it's cringe.

>>21477907 (OP)
This happens because the meat fibers shrink at different rates.
Basically the cut as it was butchered is not suitable for pan frying.
You can fix this the same way you stop pepperoni from curling on a pizza, by making indented cuts on the circumference.