"London broil" can refer to several cuts of meat, some are tougher than others. I always use flank steak, not frozen, and marinate it 12 - 24 hours. This isn't to tenderize the steak, but to add flavour. I broil flank steak for about 6 to 8 minutes each side, then tented with foil for up to 20 minutes before slicing thinly across the grain. Don't slice immediately after cooking; the resting period is important.
So I think you should thaw (in the refrigerator) and marinate the steak first.
Long enough to cook it to your liking.
2 hours
A prime rib can be frozen, but it should be thouroughly thawed before cooking.
Long enuf
12 minutes
Normally, frozen vegetables are not thawed first but are cooked from frozen.
You should cook a rotisserie chicken for about an hour. You may need to cook the chicken longer if it is frozen.
I toast mine on Broil, and watch very closely to keep from burning.
1min 30seconds in a microwave on medium high ;)
If you half cook it first, over a year.
You might have better luck asking this on CannibalAnswers.com.
It last pretty long. You can still cook it.