Quote (Centurion @ Jan 6 2012 11:49pm)
On a grill, obviously. Anything else is sacrilege, as is cooking a steak past medium.
When you're doing a topper for a steak you want to make sure that it isn't too strong, otherwise you'll drown out the subtle deliciousness of the meat you bought, provided you cook your steak no more than medium (if you don't, then you I feel sorry for you). For mushrooms and onions, heat your pan to medium high, melt butter (or EVOO) throw in your mushrooms and/or onions, add a small amount of garlic if you so desire, season with a pinch of salt and pepper and any other herb you like (very little is required), and saute until the onions have caramelized (browned) and the mushrooms have wilted.
Try harder to sound like you have any clue wtf you're talking about.