Preheat Oven 200 C
Line a baking dish with baking paper.
Season lamb to your liking with salt and pepper.
Heat large pan over high heat, brown lamb on all sides, transfer to baking dish and set aside.
Combine nuts, crumbs, butter, oil, herbs and an extra pinch of salt and pepper.
Spread the mustard over the meat side of the rack then press the pistachio mixture on top of mustard.
Bake in oven until the crust is golden and the lamb is cooked to your liking. 20-25 minutes for medium rare, 30 minutes for medium and 40 minutes for medium well.
Rest 10 minutes before serving, cutting each rack in half.
Serve with potatoes and green vegetables.