Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Trim the tough, woody ends off the asparagus spears and spread them in a single layer on the prepared baking sheet.
Drizzle the asparagus with the olive oil and sprinkle with half of the sea salt and black pepper, tossing to coat evenly.
Roast the asparagus in the oven for 12 to 15 minutes until they are tender and just starting to brown at the tips.
While the vegetables roast, season the chicken breast on both sides with the remaining sea salt and black pepper.
Heat the ghee in a medium stainless steel or cast iron skillet over medium-high heat until it is shimmering and hot.
Place the chicken in the skillet and sear for 6 to 7 minutes without moving it to develop a golden-brown crust.
Flip the chicken and cook for another 5 to 6 minutes, or until the internal temperature reaches 165°F.
Reduce the heat to low and add the minced garlic, fresh thyme, lemon zest, and lemon juice to the skillet, stirring for 1 minute to create a pan sauce.
Spoon the lemon-herb pan juices over the chicken and serve immediately alongside the roasted asparagus.