... It is probably Flap. It could come from the top piece on th rib(deckles) or the chuck ,both of which are used for chopped mest.
He is most likely referring to what is called Chuck Tail Flat, which is the "butcher's" term for Boneless
Short Ribs.
NOOOOOOOOOOOOOOOOO. These guesses are soooooooooooooooooooooo wrong -- and not in the good way either.
I would guess that flap meat is the piece above the
flank.
No. And why guess?
Unsurprisingly ChefBuba, and America's Test Kitchen website (h/t mdmphd) had it write from the giddyap.
Flap DOES come from the bottom sirloin, and NOT from the rib or chuck. If you want to check for yourself, it's IMPS 185A. The IMPS number will help if you want to order flap from a custom butcher who isn't familiar with it's common name. Meat cut names can be regional. If a cut is labeled as something other than you'd expect in a different area that doesn't mean the retailer is acting in bad faith by labeling chuck as "London Broil" as opposed to London Broil which comes from the plate or
flank. The key is to get everyone on the same page.
If you're serious about meat, you may want to put a site like
Ask the Meatman in your bookmarks. If you're serious about understanding where
beef cuts come from on the animal, or just want to pretend you know what you're talking about, you should bookmark
Bovine Myology.
Also unsurprisingly, Brian Shaw is right about finding flap in Mexican meat markets.
BDL