Whisk together Dijon mustard, garlic, olive oil, rosemary, and salt and pepper in a bowl. Place lamb chops in a large zip-top bag or other airtight container. Coat lamb with Dijon mixture on both sides. Let marinate in the fridge for at least 30 minutes, but up to 24 hours.
Position an oven rack to the highest position in the oven and line a broiler pan with aluminum foil.
Take lamb chops out of the bag and place onto prepared pan. Set oven to broil on high and place pan into the oven.
Cook lamb chops for 8 minutes, until brown, and then flip and cook for an additional 3-5 minutes depending on the doneness you like your meat. (3 minutes for medium rare, 4 for medium, 5 for well done)
If using a meat thermometer, 145 degrees will be medium rare, 160 degrees will be medium, and 170 degrees is well-done.Keep leftovers in the fridge for up to 4 days.
Serving: 1lamb chop | Calories: 446kcal | Total Carbs: 2g | Protein: 18g | Fat: 40g | Net Carbs: 2g