I love flat iron - sear high heat, cut across the grain. It's simple, nothing fancy but flat iron is such a flavorful steak that I like to let it shine.
I cook on an outdoor grill.
Usually just a brushing of olive oil and then seasoning of choice.
I usually use a Montreal Steak Rub. Other times I do a cumin, black pepper, salt, fresh cilanto plus other things marinade for 45 minutes then onto the hot grille.
3-5 minutes a side max. I'm guessin' for medium rare. Sometimes less depending upon size and thickness.
Do NOT go over medium.
Cut against the grain on an angle.
I;ve got two in the freezer.
They really are a quick and easy cut although I do love me some flank steak just as much. Sadly, flank steak is now big $$$. Ugh.
You're getting all the info you need here. I'll add only that since I'm the sole carnivore in the house (aside from the cats, who can't have any) I'll cut the steak into approximately 1" slices, have about half for supper and bag the rest. In the morning I cut each slice in half lengthwise, sizzle them quickly in hot butter and have with eggs and toast. Or save them for lunch and have cold in a sandwich.