If you actually get to try the real American cheese, you will find it is very much a real cheese (much like a ‘very’ mild cheddar). This normally involves mugging a senior citizen on the way back from getting their gov’t cheese allowance. I have no idea what happens to it once Kraft gets their hands on it.
Just to provide the full story, you cut against the grain so you chew with the grain. Most meat should be prepared this way. Otherwise you will be chewing and grinding the fibers into each other (picture tangling and knotting), not separating them apart from each other.
For the marinades, if you have a very lean cut, don’t use a lot of acid (wine, vinegar, lemon juice) as it will start to cook the meat and make it tough. Especially if you leave it overnight.
-Tcat
So SHAKES, what did you do?
Another good reason not to buy cuts of mear that are too lean. Modern farming techniques have taken so much of the flavor out of meat that it often needs the marinade. Now they cut all the fat off it so it has even less flavor, and runs the risk of being Sahara-like when cooked.
Hands off my marbling, Mr. Butcher!
I just made a London Broil last weekend, actually.
I marinated it for 4 hours or so in a Ken’s Steak House teriyaki marinade, let it get to room temperature while I heated up my broiler, and broiled it for 4 minutes on each side (as per the words of The Guru, Alton Brown.) Then I let it rest, under cover, for about 20 minutes.
It came out moist, tender, juicy…all that. I would’ve made a homemade marinade, but most of the recipes I have for decent ones suggest an overnight soak & I didn’t have that time available.
Yummy stuff. 
Agreed- but frequently customers hate paying per pound for fat. They push the butcher to strip off all of the fat and marbling as best as they can. The results are as depicted above.
You want lean? Eat ostrich.
I understand how marbling works, but what about the fat around the outside of the steak? Should that be trimmed before cooking?
It does- it is “pasturized process cheese food”, which indicates to me it is something that is fed to real cheese.
I suggest a good use for the “fat around the outside”. Beef today is -IMHO- too lean. So, when pan frying a steak, I trim (that is remove all but a small amount of) this fat, and place it in the pan, then turn on the fire. When that fat sizzles, I add the steak, which is now fried in it’s own fat. Tasty.