Preheat your oven to 400°F (200°C). Cut the top off the head of garlic, exposing the cloves. Drizzle with 1 tablespoon of olive oil, wrap in aluminum foil, and roast in the preheated oven for about 30-40 minutes, until soft and caramelized. Allow to cool slightly, then squeeze the garlic cloves out of their skins into a bowl and mash with a fork.

Season the ribeye steaks generously with salt and pepper. In a small bowl, mix the roasted garlic with the crushed fennel seeds and the remaining 1 tablespoon of olive oil. Rub this mixture all over the steaks, ensuring they are well coated.

Heat a cast-iron skillet or grill pan over medium-high heat. Once hot, add the steaks and sear for 4-5 minutes on each side for medium-rare, or until your desired doneness is reached. Remove the steaks from the pan and let them rest for about 5-10 minutes.

While the steaks are resting, cut the lemon in half. Place the lemon halves cut side down on the hot skillet or grill pan until charred, about 2-3 minutes.

In a small bowl, combine the softened butter and chopped chives. Mix well and set aside.

Slice the rested ribeye steaks and serve with the charred lemon halves and a dollop of chive butter on top. Squeeze the charred lemon over the steak before enjoying.