Prepare the Smoked Leek Compound Butter: If using a regular leek, slice it lengthwise and rinse thoroughly to remove any dirt. Sauté the leek in a pan with a bit of olive oil until soft and slightly caramelized. If using a smoked leek, skip this step. In a mixing bowl, combine the softened butter, smoked leek (chopped), fresh parsley, lemon juice, and a pinch of salt. Mix well until all ingredients are fully incorporated. Transfer the compound butter onto a piece of parchment paper or plastic wrap, shape it into a log, and refrigerate until firm.

Prepare the Steaks: Preheat your grill or skillet over medium-high heat. Pat the New York strip steaks dry with paper towels, then season both sides generously with salt and pepper. In a small bowl, mix the toasted mustard seeds and smoked paprika. Press this mixture onto both sides of the steaks, ensuring an even coating.

Cook the Steaks: Add olive oil to the hot grill or skillet. Once the oil is shimmering, place the steaks in the pan. Cook for about 4-5 minutes on one side without moving them to get a nice crust. Flip the steaks and cook for another 4-5 minutes for medium-rare, or until your desired doneness is reached. Remove the steaks from heat and let them rest for about 5 minutes.

Serve: Slice the steaks against the grain and serve topped with a generous dollop of the smoked leek compound butter.