Recipe Instructions:
2 large bone-in T-bone or ribeye steaks (see Kenji's note below)
Kosher salt and freshly ground black pepper
1/2 cup (120ml) vegetable or canola oil
6 tablespoons (90g) unsalted butter
12 sprigs thyme or rosemary (optional)
1 cup finely sliced shallots (about 2 large; optional)
Carefully pat steaks dry with paper towels. Season liberally on all sides, including edges, with salt and pepper. If desired, let steak rest at room temperature for 45 minutes, or refrigerated, loosely covered, up to 3 days (see Kenji's note below).
In two 12-inch heavy-bottomed cast iron skillets, divide oil and heat over high heat until just beginning to smoke. Carefully add steak and cook, flipping frequently (about every 30 seconds), until a pale golden-brown crust starts to develop, about 4 minutes total.
Divide butter, herbs (if using), and shallot (if using) between skillets and continue to cook, flipping steak occasionally and basting any light spots with foaming butter, using a spoon. If butter begins to smoke excessively or steak begins to burn, reduce heat to medium. To baste, tilt pan slightly so that butter collects by handle. Use a spoon to pick up butter and pour it over steak, aiming at light spots. Continue flipping and basting until an instant-read thermometer inserted into thickest part of tenderloin side registers 120 to 125° F (49 to 52° C) for medium-rare or 130° F (54° C) for medium, 8 to 10 minutes total. Immediately transfer steak to a large heatproof plate and pour pan juices on top. Let rest 5 to 10 minutes. Carve and serve.
Kenji's notes: This recipe is designed for very large steaks, at least one and a half inches thick and weighing 24 to 32 ounces (700 to 900 grams) with the bone in. Porterhouse, T-bone, ribeye, or New York strips will all work. Avoid using tenderloin steaks, as they are likely to overcook. For better results, let steaks rest at least 45 minutes at room temperature, or up to three days loosely covered in the refrigerator, after seasoning in step 1.
Kristen's note: Buying two steaks to cook side-by-side is expensive but fun (as described in the original article linked above in the headnote), but the recipe can be easily halved if you prefer.