2 racks of lamb, trimmed 1 teaspoon herbes de Provence salt and ground black pepper to taste 1 tablespoon vegetable oil ⅔ cup chopped pistachio nuts 2 tablespoons dry bread crumbs 1 tablespoon melted butter 1 teaspoon olive oil 3 tablespoons Dijon mustard
Preheat the oven to 400 degrees F (200 degrees C). Line a baking sheet with aluminum foil. Generously season each rack of lamb with herbes de Provence, salt, and pepper.
Heat vegetable oil in a large skillet over high heat. Place lamb into the skillet and cook until browned on all sides, 6 to 8 minutes. Transfer to the prepared baking sheet.
Stir pistachios, bread crumbs, melted butter, and olive oil together in a small bowl; season with salt and pepper. Spread mustard over the fatty side of lamb, then press pistachio mixture into mustard.
Bake in the preheated oven until crust is golden and lamb is pink in the center, 20 to 25 minutes. An instant-read thermometer inserted into the center should read at least 130 degrees F (54 degrees C) for medium doneness.
Transfer lamb to a plate and let rest for 10 minutes before slicing. Enjoy!