Preparation Preheat oven to 450°F. Season steaks all over with pepper and 1 1/2 tsp. kosher salt. Let sit 10 minutes. Meanwhile, toss broccolini, oil, and 1/2 tsp. kosher salt on a rimmed baking sheet to combine. Spread out in a single layer and set aside. Using tongs if needed, hold both steaks together fat cap side down in a large ovenproof skillet, then set over high heat. Cook until pan is coated in fat, about 4 minutes. Lay steaks flat and continue to sear until deeply browned, about 3 minutes per side. Transfer skillet to oven and roast steaks until an instant-read thermometer inserted into the thickest part registers 120°F for medium-rare, 6–8 minutes. Transfer to a cutting board and let rest 10 minutes before slicing. While steaks are resting, roast reserved broccolini until crisp-tender and lightly charred, about 10 minutes. Heat cheese, cream cheese, milk, nutmeg, cayenne, and remaining 1/4 tsp. kosher salt in a medium saucepan over medium, whisking constantly, until a smooth sauce forms, about 5 minutes. Divide sauce among plates. Top with broccolini and steaks; sprinkle with sea salt.
Preparation Preheat oven to 450°F. Season steaks all over with pepper and 1 1/2 tsp. kosher salt. Let sit 10 minutes. Meanwhile, toss broccolini, oil, and 1/2 tsp. kosher salt on a rimmed baking sheet to combine. Spread out in a single layer and set aside. Using tongs if needed, hold both steaks together fat cap side down in a large ovenproof skillet, then set over high heat. Cook until pan is coated in fat, about 4 minutes. Lay steaks flat and continue to sear until deeply browned, about 3 minutes per side. Transfer skillet to oven and roast steaks until an instant-read thermometer inserted into the thickest part registers 120°F for medium-rare, 6–8 minutes. Transfer to a cutting board and let rest 10 minutes before slicing. While steaks are resting, roast reserved broccolini until crisp-tender and lightly charred, about 10 minutes. Heat cheese, cream cheese, milk, nutmeg, cayenne, and remaining 1/4 tsp. kosher salt in a medium saucepan over medium, whisking constantly, until a smooth sauce forms, about 5 minutes. Divide sauce among plates. Top with broccolini and steaks; sprinkle with sea salt.