Preheat your oven to 400°F (200°C). Slice the top off the head of garlic, drizzle with olive oil, and wrap in aluminum foil. Roast in the oven for about 30-35 minutes, until the cloves are soft and caramelized. Remove and let cool.

While the garlic is roasting, take the ribeye steaks out of the refrigerator and let them come to room temperature for about 30 minutes. Rub the steaks with olive oil, then season generously with za'atar, salt, and pepper on both sides.

Heat a cast-iron skillet or grill pan over medium-high heat. Once hot, add the ribeye steaks and sear for about 4-5 minutes on each side for medium-rare, adjusting the time for your preferred doneness. Remove the steaks from the pan and let them rest for at least 5 minutes before slicing.

In the same skillet, reduce the heat to medium and add the finely chopped shallots. Sauté for about 5-7 minutes, stirring frequently until they are soft and caramelized.

Squeeze the roasted garlic cloves out of their skins into a mixing bowl. Add the sautéed shallots, softened butter, fresh thyme, lemon juice, salt, and pepper. Using a fork or a hand mixer, whip until smooth and well combined.

Slice the ribeye steaks against the grain and place on a serving platter. Top with generous dollops of the whipped caramelized shallot butter. Serve immediately with your favorite side dishes.