5 years ago i posted a reply to the very same question... comes out great...
take a can of coke, pepsi, dr. pepper or the like... pour it over the steak in a glass dish, covered over night...
in a hot skillet melt two tbs butter, saute coarse chopped onions and green pepper till soft... season the steak with pepper and skittle in the pan 2 minutes to the side... remove to a cutting board and cover loosely for a few minutes more... slice diagonally in thin strips across the grain... pour the run-off juices over the top with the onion and peppers...
of course you're gonna have more than just steak so do this with time to spare...
italian dressing does the same but with different flavor...