1/4 c plus 1 T olive oil
1 large porterhouse steak, about 1 1/2 lbs and 2-inches thick, at room temperature
salt, preferably gray salt
freshly ground black pepper
3 large red onions
1 T minced garlic
1 T finely chopped fresh thyme leaves
1/4 cubalsamic vinegar
preheat the oven to 450 degrees.
in a heavy skillet over med-hi heat, add 1 T olive oil and heat until very hot. season the steak with salt and pepper. turn on the exhaust fan and put the steak in the pan; stand back to prevent being splattered. cook until the steak is brown on the first side, about 2 mins; brown on the other side. remove the steak to a rack or baking pan until you are ready to finish cooking it. when ready, put the steak into the oven and cook until done to your liking, about 10 mins for rare. remove the steak to a carving board and let it rest for 5 minutes.
peel and cut the onions into thirds or quarters, depending on their size. leave as much root on as possible to keep the wedges from falling apart. heat 1/4 c olive oil in the same skillet used to cook the meat over med-hi heat until hot. add the onions, reduce the heat to med, and cook until brown on all sides, about 5 mins. season them with salt and pepper. place the pan of onions in the oven and roast until tender and very browned (the onions tend to char around the edges), 15 to 20 mins.
remove the onions from the oven, add the garlic, and cook briefly until light brown. add the thyme and stir. add the vinegar (stand back so as to not get splattered) and toss well with the onions. stir and scrape up all the browned bits clinging to the bottom of the pan.
to serve, cut the meat off the bone, then carve it into thin slices. serve immediately.
note: in order to cook the meat in the shortest amount of time and thus extract the most flavor, the meat must be at room temperature. afterward, the meat must rest before carving. if this procedure is followed, the carving knife glides right through the steak.
a 1 1/2 lb porterhouse should give you about 14 oz of meat off the bone, enough for 3 or even 4 people. however, if you are steak lovers, you might want to buy 2 steaks of that size for 4 people.