Spiced with mustard and redolent of herbs, the crunchy crust for this classic roast is prepared with fresh bread crumbs. To make them, process cubes of rustic bread in a food processor until finely ground. Follow these step-by-step instructions on how to french a rack of lamb.
- 2 (1 3⁄4) lb. frenched and trimmed rib racks of lamb
- Kosher salt and freshly ground black pepper, to taste
- 1⁄2 cup flour
- 4 Tbsp. Dijon mustard
- 3 eggs, beaten
- 2 cups cubed (1") country white bread
- 2 Tbsp. each chopped fresh rosemary and fresh flat-leaf parsley
- 1 Tbsp. chopped fresh thyme
- 1⁄2 cup canola oil
Heat oven to 450˚. Season lamb with salt and pepper; set aside. Put flour on a plate; set aside. Whisk together mustard and eggs and transfer to a shallow baking dish; set aside. Put bread cubes into bowl of food processor and process until finely ground. Add herbs and season with salt and pepper. Pulse twice to combine and transfer half of the bread crumb mixture to a plate. Working with 1 lamb rack at a time, roll the rack in the flour, shaking off excess, dip in the mustard–egg wash, and roll and press the rack into the bread crumb mixture; transfer to a plate.
Heat 1⁄4 cup oil in a 12" cast-iron skillet over medium-high heat. Add 1 lamb rack fatty side down and cook, using tongs to flip and brown the bottom and back of the rack, until the crust is browned, about 10 minutes. Transfer lamb to a rimmed baking sheet fitted with a rack. Wipe out the skillet and repeat with remaining oil and lamb. Transfer the baking sheet to the oven and bake lamb until an instant-read thermometer inserted into center of the thickest part of the meat reads 130˚. Let cool for 5 minutes before slicing into chops and serving.