For the leeks: Preheat the oven to 475 degrees F. Line a baking sheet with a wire rack.
Put the whole leeks on an unlined sheet tray and bake, flipping halfway through, until completely charred, about 20 minutes. Allow to cool to the touch.
For the cocoa blackened steak: Combine the smoked paprika, cocoa powder, onion powder, cumin, garlic powder, smoked salt, sugar and coffee in a bowl. Divide the mixture between the each of the rib eyes and let sit for 15 minutes.
For the leeks: Once the leeks are cool to the touch, remove the outer layers, revealing the soft leeks inside. Finely chop the leeks and add to a bowl. Add the cocoa nibs, olive oil and red wine vinegar and season with the smoked sea salt. Taste and adjust the seasoning.
For the Marcona almond romesco: Blend the peppers, olive oil, white chocolate, tomatoes, sherry vinegar, smoked paprika, salt and garlic in a blender until smooth. Add the almonds to a food processor and pour over the blended sauce. Pulse until coarse, not smooth.
Heat a 14-inch cast-iron skillet over medium-high heat. Add 2 tablespoons cooking oil and the steaks and cook on both sides until evenly charred, about 7 minutes per side, searing in batches if needed. Remove from the skillet and put on the rack on the sheet tray. Let rest for 10 minutes before slicing.
Serve the steak alongside the romesco and the leek condiment.