This is a great bachelor’s dinner, but you can certainly make more at the same time, in a larger pan. My favorite salad with a steak is torn Bibb lettuce dressed with a little olive oil, sea salt, and some brine from a bottle of cornichons (or any pickle juice) instead of vinegar. Remember, mushrooms hold a lot of water, so don’t put them under running water, or submerge them, which can make them soggy.
1 small strip steak some button mushrooms, or whatever fresh mushroom you prefer, or a mix a good glug of good Port a good glob of good butter about 1 teaspoon table salt (not sea salt) ground black pepper
Gently clean the mushrooms with a damp towel. Cut them into halves or quarters, but make them all the same size so they cook evenly. Heat a small, cast iron skillet (important) over high flame with enough table salt to lightly cover the bottom of the skillet. You want a hot pan; use a mitt. Generously pepper one side of the steak, and quickly place that side down in the hot pan. You can’t adjust it without tearing the meat, so be deft about it. Lower the flame to medium-high, and sear the steak without moving it for 3-4 minutes. The steak should release easily from the pan when lifted with a fork; if not, try again after a minute or so. Pepper the rare side of the steak, lift it from the pan, salt the pan again slightly, and turn the steak back into the pan. Lower the heat to medium, and sear as before for 4-5 minutes. (At 8 minutes the steak will be rare.) Put the steak on a plate, preferably a hot one. With the pan off the heat, pour a good glug, about ½ cup, into the pan, return to a low flame, and deglaze with a wooden spatula (better than a spoon, more surface). Melt the butter in the now meaty port, and ad the mushrooms. Toss to coat them well, add salt, but not too much. Cover with the lid askew, and let the mushrooms stew in the butter for 3 or for minutes, tossing once. Return the steak to the pan quickly for last-minute heat, and eat from the pan with the salad on the side.