Preheat the oven to 400°F (200°C).

Cut the top off the head of garlic to expose the cloves. Drizzle with 1 tablespoon of olive oil, wrap in aluminum foil, and roast in the preheated oven for about 30-35 minutes, or until the cloves are soft and caramelized.

While the garlic is roasting, prepare the sirloin steak. Season both sides generously with salt and pepper. Rub the bergamot zest all over the steak.

Heat a large skillet over medium-high heat. Add 1 tablespoon of olive oil. Once hot, sear the steak for about 4-5 minutes on each side until a nice brown crust forms.

Transfer the seared steak to a baking dish. Once the garlic is finished roasting, squeeze the softened garlic cloves out of their skins and mix them with the softened butter, thyme, and lemon juice in a bowl. Season with salt and pepper to taste.

Spread the garlic-thyme butter over the top of the steak.

Place the baking dish in the oven and roast for an additional 10-15 minutes, or until the steak reaches your desired doneness (medium-rare is about 135°F or 57°C).

Remove the steak from the oven and let it rest for 10 minutes before slicing.

Serve the sliced steak with lemon wedges and drizzle any remaining garlic-thyme butter on top.