Preheat your oven to 400°F (200°C).

Season the top sirloin steak generously with salt and pepper on both sides.

In a large oven-safe skillet, heat 1 tablespoon of olive oil over medium-high heat. Add the seasoned steak and sear for about 4-5 minutes on each side, until a golden-brown crust forms.

Once seared, remove the skillet from heat. Spread the minced garlic and chopped sage over the steak.

Arrange the halved spring onions around the steak in the skillet. Drizzle with the remaining tablespoon of olive oil, and season with salt and pepper.

Transfer the skillet to the preheated oven and roast for about 15-20 minutes, or until the steak reaches your desired level of doneness (135°F for medium-rare).

While the steak is roasting, in a small bowl, combine the softened butter, chopped chives, lemon juice, lemon zest, and a pinch of salt. Mix until well combined and set aside.

Once the steak is cooked, remove it from the oven and let it rest for about 10 minutes before slicing.

Slice the steak against the grain and serve with the roasted spring onions. Top each serving with a dollop of chive butter.