1 3-lb., 2″-thick porterhouse steak, at room temperature Kosher salt and freshly ground black pepper, to taste 2 tbsp. canola oil 4 tbsp. unsalted butter 6 sprigs thyme 1 lemon, halved crosswise
1. Season steak heavily on both sides with salt and pepper; let sit for 30 minutes. Heat oven to 500°. Heat a 12″ cast-iron skillet over high heat until it begins to smoke. Add oil and steak; cook until lightly charred on one side, about 5 minutes. Flip steak, and transfer skillet to oven; cook until medium-rare and an instant-read thermometer reads 135°, about 10 minutes. Transfer steak to a platter, and let rest for 10 minutes.
2. Meanwhile, pour off pan drippings and return skillet to stove over high heat. Add butter and then thyme and lemon halves, cut sides down; cook until golden brown, about 4 minutes. Remove from heat. Slice steak around the bone. Transfer to plates, and drizzle with butter from skillet. Serve with the lemon for drizzling.