Pat the sirloin steak dry with paper towels and season both sides evenly with sea salt and black pepper.
Heat a cast-iron skillet over medium-high heat and add half of the ghee, allowing it to melt and shimmer.
Place the steak in the hot skillet and sear for 4-5 minutes per side for medium-rare, or until your desired level of doneness is reached.
During the last 2 minutes of cooking, add the remaining ghee, minced garlic, rosemary, and thyme to the pan.
Tilt the pan slightly and use a spoon to continuously baste the steak with the melted herb-infused ghee.
Remove the steak from the pan and let it rest on a cutting board for at least 5 minutes to lock in the juices.
While the steak rests, add the green beans to the same skillet and sauté for 3-4 minutes until bright green and tender-crisp.
Finish the green beans with a squeeze of lemon juice and serve alongside the rested steak.