There are a number of reasons to pound a piece of meat madly before cooking it, though not all of them make sense.
For example, one reason you often hear is that it saves you time — that by flattening the meat first, or so the theory goes, you can cook the meat that much faster. Which of course you can: that part is inarguable. But the extra time it will take to flatten the meat is probably, if anything, going to be longer than the time it would take to simply cook the original piece.
There are other, better reasons for pounding, however. By broadening the meat’s surface area, you increase the amount of meat that browns and becomes crisp during cooking. In these cases, making a paillard — or, if you like, a cutlet or a scallop — is definitely the way to go. All you need to do is take a boneless cut of meat at least half an inch thick, slice into it horizontally and open it up like a book. (Alternatively, cut through it all the way so you end up with two pieces).
Then flatten it.
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