Season the steak to taste with salt and pepper. Sear on one side, flip, and into the oven to almost finish. Remove from the oven, remove the steak from the pan and keep warm. Return the pan to the heat, add a little butter/oil if needed, some sliced shallots and mushrooms (sliced portobellos would be good), saute until limp, add a splash of soy (about 1 T), some red wine, and beef stock. Simmer until almost all the liquid is gone, and top the steak with this mixture.
If you have beef demi-glace on hand, that would be better than the stock. You can also leave out the mushrooms, saute the shallots, deglaze with brandy or cognac, add some demi and some good mustard, like a whole-grain dijon. Salt and pepper to taste