01 -
Preheat oven to 390°F, middle shelf.
02 -
Sprinkle lamb with salt and pepper. Heat 1 tbsp oil in a skillet on high, sear all sides 1.5 minutes each. Cool 5 minutes.
03 -
Mix Dijon, rosemary, garlic, and 3 tsp egg in a small bowl.
04 -
Mix Panko, parmesan, garlic, salt, pepper, and rosemary in a bowl, then stir in melted butter. Spread on a plate.
05 -
Spread mustard mix on lamb underside, press into crumbs, then coat top and ends, pressing into crumbs.
06 -
Place lamb on a rack in a tray. Roast 20 minutes for Frenched, 30-35 for untrimmed, until 140°F inside.
07 -
Rest lamb 5 minutes under foil, then slice into 2-3 bone portions with a sharp knife.
08 -
Boil wine and stock until reduced by 3/4, whisk in cream and mustard, simmer 3-5 minutes until thickened.