Can I let my flank steak marinate for 48 hrs? It's in olive oil, garlic, lemon slices and seasonings.
That's a pretty long time -- assuming it's refrigerated, but even so, the acid in the lemon juice (and salt if you're using it) might start to break down the meat. If you can cook it within 24 hours, I would.
I've frozen a flank steak in its marinade when I needed to take it to a potluck BBQ. I removed it from the freezer earlier in the day and allowed it to slowly defrost in the fridge. By the time I drove to the BBQ, it was nicely marinated and defrosted. Worked beautifully. The recipe was from Jerry Traunfeld's Herbfarm Cookbook which is my standard flank steak preparation.