Preheat your oven to 400°F (200°C) and line a small baking sheet with parchment paper.
Trim the woody ends off the asparagus spears and place them on the baking sheet.
Drizzle the asparagus with olive oil and season with half of the sea salt and black pepper, tossing to coat evenly.
Roast the asparagus for 12-15 minutes until tender and slightly charred at the tips.
While the asparagus roasts, pat the sirloin steak dry with paper towels and season both sides with the remaining salt and pepper.
Heat a cast-iron or heavy skillet over medium-high heat until very hot.
Place the steak in the dry skillet and sear for 3-4 minutes per side for medium-rare.
During the last 2 minutes of cooking, add the ghee, smashed garlic cloves, and rosemary to the pan.
Tilt the pan slightly and use a spoon to continuously baste the steak with the melted herb garlic ghee.
Remove the steak from the pan and let it rest on a cutting board for 5 minutes before slicing against the grain.
Serve the sliced steak alongside the roasted asparagus, drizzling any remaining pan juices over the meat.