Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Trim the Brussels sprouts and cut them in half, then peel and slice the carrots into half-moons.
Toss the vegetables on the baking sheet with 1 tsp of olive oil and a pinch of salt and pepper.
Roast the vegetables for 20-25 minutes, tossing halfway through, until they are tender and caramelized.
In a small bowl, combine the almond meal, dried rosemary, and dried thyme.
Pat the lamb loin dry with a paper towel and season all sides with the remaining sea salt and black pepper.
Brush the top and sides of the lamb with Dijon mustard, then press the herb and almond mixture firmly onto the meat.
Heat the remaining 1 tsp of olive oil in an oven-safe skillet over medium-high heat.
Sear the lamb for 2-3 minutes on the bottom side (non-crusted) until golden brown.
Carefully flip the lamb or place the skillet directly into the oven for 6-8 minutes until the internal temperature reaches 135°F for medium-rare.
Remove the lamb from the oven and let it rest on a cutting board for 5 minutes before slicing into thick medallions.
Serve the herb-crusted lamb alongside the roasted vegetables.