Prepare the Black Garlic Compound Butter: In a small bowl, combine the softened unsalted butter, mashed black garlic, chopped chives, fresh thyme leaves, garlic powder, onion powder, and Dijon mustard. Mix well until all ingredients are fully incorporated.

Place the compound butter on a piece of plastic wrap, shape it into a log, and wrap tightly. Refrigerate for at least 30 minutes to firm up.

Prepare the Steaks: Preheat your oven to 400°F (200°C). Pat the New York strip steaks dry with paper towels. Brush both sides with olive oil and season generously with salt and black pepper.

Sear the Steaks: Heat a large oven-safe skillet over medium-high heat. Once hot, add the seasoned steaks and sear for about 3-4 minutes on each side until a golden-brown crust forms.

Roast the Leeks: While the steaks are searing, in a separate pan, add a drizzle of olive oil and the sliced leeks. Sauté over medium heat until they are soft and slightly caramelized, about 5-7 minutes. Season with a pinch of salt and pepper.

Combine and Roast: Once the steaks are seared, remove them from the heat. Top each steak with the sautéed leeks and a generous amount of the chive-crusted topping. Transfer the skillet to the preheated oven and roast for an additional 8-10 minutes, or until the desired internal temperature is reached (130°F for medium-rare).

Serve: Remove the skillet from the oven and let the steaks rest for 5 minutes. Slice the chilled black garlic compound butter into rounds and place a slice on each steak just before serving. Garnish with additional fresh chives, if desired.