Remove the lamb chops from the refrigerator 20-30 minutes before cooking so they come closer to room temperature. Pat them very dry with paper towels, then season generously on both sides with kosher salt and black pepper.

Heat the olive oil in a heavy skillet (cast iron works best) over medium-high heat until it shimmers and just starts to smoke lightly.

Place the lamb chops in the hot skillet in a single layer, working in batches if needed to avoid crowding. Sear for 3-4 minutes on the first side without moving them, until a deep golden-brown crust forms.

Flip the chops and sear for another 3 minutes on the second side. Add the butter, crushed garlic, rosemary, and thyme to the pan.

Tilt the skillet slightly and continuously spoon the melted herb butter over the chops for 1-2 minutes, basting until the internal temperature reaches 145F for medium (use an instant-read thermometer inserted into the thickest part, avoiding bone).

Transfer the chops to a plate, tent loosely with foil, and rest for 3 minutes before serving; this allows the internal temperature to finish carryover cooking safely and keeps the juices in.

While the chops rest, pour off excess fat, return the skillet to medium heat, and pour in the stock along with the balsamic vinegar, scraping up the browned bits from the bottom of the pan. Simmer for 2-3 minutes until slightly reduced, then spoon the pan sauce over the rested lamb chops and serve immediately.