1Rub steaks all over with 1 Tbsp. oil and season generously with salt. Heat 2 Tbsp. oil and 1 Tbsp. butter in a medium saucepan over medium-low. Cook shallot, stirring often, until golden brown, 10–15 minutes. Remove from heat and carefully add 1/4 cup cognac. Bring mixture to a simmer over medium-low heat and cook, stirring occasionally, until cognac is reduced by half, about 5 minutes. Stir in cream and black pepper and bring to a simmer. Cook, swirling occasionally, until cream is slightly thickened, about 5 minutes; let cool slightly.
3Heat remaining 2 Tbsp. oil in a large cast-iron skillet over high. Add steaks and cook, occasionally lifting steaks to allow hot oil to flow underneath, until a brown crust forms underneath, about 4 minutes. Turn steaks and cook until crust forms on the other side and an instant-read thermometer inserted into the thickest part registers 125°F for medium-rare, about 4 minutes. Transfer steaks to a cutting board and let rest 10 minutes. Reserve skillet.