Preheat your oven to 400°F (200°C). Dice the Yukon Gold potatoes into 1/2-inch cubes and trim the woody ends off the asparagus spears.
On a parchment-lined baking sheet, toss the diced potatoes with the olive oil and half of the sea salt and black pepper. Spread them in a single layer.
Roast the potatoes for 15 minutes. Remove the tray, add the asparagus to the other side of the sheet, and roast for another 10 minutes until the potatoes are golden and the asparagus is tender.
While the vegetables roast, pat the steak dry with a paper towel and season both sides with the remaining sea salt and black pepper.
Heat a cast-iron skillet over medium-high heat. Once hot, add the ghee and place the steak in the pan, searing for 3-4 minutes on the first side.
Flip the steak and add the smashed garlic cloves, rosemary, and thyme to the pan. Tilt the pan slightly and use a spoon to baste the steak with the hot herb-infused ghee for the final 3 minutes of cooking.
Remove the steak from the skillet and let it rest on a cutting board for at least 5 minutes to allow the juices to redistribute.
Slice the steak against the grain and serve immediately alongside the crispy roasted potatoes and asparagus.