OP, any acid (citrus or vinegar) will help to tenderize any kind of meat. It's the same principle used for making Ceviche. The acid in the citrus juice "cooks" the seafood.

OP here: Thanks for the suggestions for now and later. I had no other options thawed, so I went vigilante and it worked. Mixed 3TBPs Dijon mustard with a TBP of white vinegar, and microwaved. I did know that white vinegar helps with toughness and heating up helps a marinade lock in with less time. Salted with sea salt, rubbed it, let sit for45 minutes, and seared on a hot hot grill. It was actually better than my regular marinating recipes!

I'll have to try the seltzer suggestion another forgetful day.

(And yes, always cut against the grain!)

Anonymous wrote:

Anonymous wrote:You are confusing two different concepts. Salt (but not sugar) penetrates deeply but is not what causes tenderization in marinades. A tenderizing marinade would need to be in contact with the meat for substantially longer than OP has to have substantial effect. My point is: (1) if you are marinating for flavor development, overnight versus 30 minutes versus brushing during grilling vs a dry rub all have similar results so OP can still use the original marinade for flavoring; and (2) how it's sliced is more important than tenderizing marinade no matter how long the marinade has to work.

Exactly why she should wait until tomorrow.

Flank steak is a crappy cut with a lot of connective tissue. Though people may think they are imparting flavor with marinade (and they do) most all marinades have a ton of salt or citrus or some sort of yogurt/buttermilk because it has the effect of tenderizing (sometimes too much in the case of yogurt).

Sure, I think everyone knows how flank steak is cut, but you will not cut your way through one of the toughest cuts of meat found on a side of beef.

"Everyone" also knows that the tougher cuts of meat have more flavor. Filet mignon is the most tender and least flavorful steak, which is why it requires a sauce. Good cooks can use technique to make your so called "crappy" cutsof meat delicious.

Salt and pepper the steak -- add cumin and/or chili powder if you like. Grill or pan sear to medium rare. Rest. Slice thinly against the grain. Squeeze half a lime over the slices. Done.

Anonymous wrote:I would marinate it tonight and save it for tomorrow.

I agree with this.

Yep, me too.

However, there is another way to go: Milanesas (cutlets).

Wrap the flank steak in something (butcher paper, parchment paper, plastic wrap) and put it on a cutting board.
Pound it flat with something heavy, like a skillet. (Or a meat tenderizing hammer would work, but a skillet's more effective). The pounding will tenderize it.

Prepare three dredging plates/trays: one with flour (seasoned with salt and pepper), one with a couple of beaten eggs, and one with either bread crumbs or, better yet for this application, crushed saltines.

Cut the pounded steak into individual portions. Dredge each one in (1) flour, (2) egg wash, (3) crumbs.

Meanwhile, you've prepared a large skillet with 1/4" or so of oil in the bottom, heated to 375. Pan-fry the dredged cutlets to crispy golden brown. Add more salt and pepper.

These are yummy as they are. If you make a cream gravy in addition, you have chicken fried steak.

Anonymous wrote:You are confusing two different concepts. Salt (but not sugar) penetrates deeply but is not what causes tenderization in marinades. A tenderizing marinade would need to be in contact with the meat for substantially longer than OP has to have substantial effect. My point is: (1) if you are marinating for flavor development, overnight versus 30 minutes versus brushing during grilling vs a dry rub all have similar results so OP can still use the original marinade for flavoring; and (2) how it's sliced is more important than tenderizing marinade no matter how long the marinade has to work.

Exactly why she should wait until tomorrow.

Flank steak is a crappy cut with a lot of connective tissue. Though people may think they are imparting flavor with marinade (and they do) most all marinades have a ton of salt or citrus or some sort of yogurt/buttermilk because it has the effect of tenderizing (sometimes too much in the case of yogurt).

Sure, I think everyone knows how flank steak is cut, but you will not cut your way through one of the toughest cuts of meat found on a side of beef.

Anonymous wrote:Fajitas.

Also, the marinade doesn't really penetrate that far into the meat. You could marinate it only for 30 minutes and then also brush the marinade on it halfway through cooking to get the same flavor. As far as tenderness goes, cutting against the grain is much more important than the marinade.

Addition of seltzer or carbonated water to the marinade helps with tenderizing.

You are confusing two different concepts. Salt (but not sugar) penetrates deeply but is not what causes tenderization in marinades. A tenderizing marinade would need to be in contact with the meat for substantially longer than OP has to have substantial effect. My point is: (1) if you are marinating for flavor development, overnight versus 30 minutes versus brushing during grilling vs a dry rub all have similar results so OP can still use the original marinade for flavoring; and (2) how it's sliced is more important than tenderizing marinade no matter how long the marinade has to work.

Anonymous wrote:Fajitas.

Also, the marinade doesn't really penetrate that far into the meat. You could marinate it only for 30 minutes and then also brush the marinade on it halfway through cooking to get the same flavor. As far as tenderness goes, cutting against the grain is much more important than the marinade.

Yes it does. Especially if the marinade has salt and sugar in it. marinating is essentially brining-it breaks down the connective tissues and makes it tender.

Anonymous wrote:I would marinate it tonight and save it for tomorrow.

I agree with this.

Also, pretty much any spice rub will work. Just libeally apply it and let it cure for a few minutes while the pan gets hot.

Fajitas.

Also, the marinade doesn't really penetrate that far into the meat. You could marinate it only for 30 minutes and then also brush the marinade on it halfway through cooking to get the same flavor. As far as tenderness goes, cutting against the grain is much more important than the marinade.

As gross as this sounds, mix French dressing and I think soy sauce - it is shocking how good it tastes...

I would marinate it tonight and save it for tomorrow.

I forgot to put the flank steak into marinate. Any suggestions for a non-marinated recipe for dinner tonight (that doesn't taste like gristle).