Make the steak: Mix the cocoa powder, both paprikas, brown sugar, cayenne and 2 teaspoons salt; rub on the steak and bring to room temperature, 30 minutes.
Make the gravy: Cook the bacon in a large skillet over medium heat, stirring, until crisp, about 5 minutes. Remove to paper towels with a slotted spoon; set aside. Add the leek to the drippings and cook until soft, about 3 minutes. Add the flour and cook, stirring, 1 minute.
Remove the skillet from the heat. Add the whiskey, then return to medium heat; if the alcohol ignites, let the flames die out. Bring to a simmer and cook, stirring occasionally, until slightly thickened, about 2 minutes. Add the chicken broth and bay leaves. Bring to a boil over medium-high heat and cook until the mixture is reduced by one-quarter, about 8 minutes. Whisk in the heavy cream and simmer, stirring occasionally, until the gravy coats a spoon, about 7 minutes. Stir in the butter, reserved bacon and parsley; season with salt and pepper. Keep warm.
Heat a large cast-iron skillet over high heat, about 3 minutes. Add 1 tablespoon butter; when it melts, add the steak and sear until a dark crust forms, about 8 minutes per side. Transfer to a cutting board and let rest 5 minutes. Season with salt. Slice and serve with the gravy.
Photograph by Anna Williams
Recipe courtesy Food Network Magazine