Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper.
Trim the woody ends off the asparagus and break the cauliflower into bite-sized florets.
Place the vegetables on the baking sheet, drizzle with half of the olive oil, and sprinkle with half of the salt and pepper.
Toss the vegetables to coat evenly and roast in the oven for 15-18 minutes until tender and slightly browned.
While vegetables roast, finely mince the rosemary, thyme, and garlic, then combine them in a small bowl with the remaining salt and pepper.
Pat the lamb chops dry with a paper towel, brush both sides with Dijon mustard, and press the herb mixture firmly onto the meat.
Heat a cast-iron skillet over medium-high heat with the remaining olive oil until shimmering.
Sear the lamb chops for 3-4 minutes per side for medium-rare, or until they reach your desired level of doneness.
Remove the lamb from the skillet and let it rest on a cutting board for 5 minutes to allow the juices to redistribute.
Plate the succulent herb-crusted lamb chops alongside the roasted asparagus and cauliflower and serve immediately.