These are divine and so easy and quick. For me living in Los Angeles, the best lamb to buy is New Zealand lamb and Trader Joes sell a great rack of lamb, unfrozen and vacuum packed.
Be careful not to overcook the lamb and 25 minutes is the perfect time for me to achieve this color above. I have been known to double the mustard/herb topping
This is a recipe from the Barefoot Contessa and is bulletproof.
1 1/2 tbsp Kosher salt
2 tbsp minced fresh rosemary
3 large garlic cloves, minced
1/2 cup good Dijon mustard
1 tbsp balsamic vinegar
2 racks of lamb, “frenched” Trader Joes has already done this for you
Preheat the oven to 450 degrees F
In the bowl of a food processor fitted with a steel blade, process the salt, rosemary and garlic until they’re as finely minced as possible. Add the mustard and balsamic vinegar and process for 1 minute.
Place the lamb in a roasting tin, not too deep, with the ribs curving down and coat the tops with the mustard mixture.
Allow the lamb to stand for 1 hour at room temperature.
Roast the lamb for exactly 20 minutes for rare or 25 minutes for medium rare.
Remove from the oven and cover with aluminum foil
Allow to sit for 15 minutes, then cut into individual ribs and serve