Stir together bread crumbs, parsley, mint, rosemary, salt, and pepper in a bowl, then drizzle with 2 1/2 tablespoons oil and toss until combined well. (I whirl it all together in my Braun chopper.)

Put oven rack in middle position and preheat to 400°F. Season lamb with salt and pepper. Heat remaining tablespoon oil in a large heavy skillet over moderately high heat until hot but not smoking, then brown lamb 1 rack at a time, turning once, about 4 minutes per rack. Transfer to a 13- by 9- by 2-inch roasting pan, arranging fatty sides up.

Spread fatty sides of each rack with 2 teaspoons mustard. Divide bread crumb mixture into 3 portions and pat each portion over mustard coating on each rack, gently pressing to adhere.

Roast lamb until thermometer inserted diagonally 2 inches into center (do not touch bone) registers 130°F (for medium-rare), 20 to 25 minutes, and transfer to a cutting board. Let stand 10 minutes, then cut into chops. For those who liked it more well cooked then cook until the internal temp reaches 160.