Preheat oven to 220°C. Cooking time: for a medium-cooked joint, allow an average of 15 minutes for every 500g, plus 15 minutes more. Usually 1hr 15/30 minutes is enough for a 1.5 – 2kg joint.
Peel the garlic, and rinse and spin dry the rocket
Place the pistachios, garlic, pine nuts, grated Parmesan, rocket and a little seasoning in a food processor and grind to small breadcrumb size. On the slowest setting, drizzle in one or two tablespoons olive oil until you have a thick, semi-dry ‘pesto’.
Beat the egg yolk and milk together.
Dust the lamb joint lightly with some seasoned the flour, shaking off the excess. Then, using a pastry brush, coat it with the egg mix.
Press the pistachio pesto firmly onto the lamb. Drizzle over a soup spoon of olive oil.
Place in a roasting tin and bake for around 1.25 – 1.5 hrs depending on the size of joint and to your preference – rare, medium or well done. Cover mid-way through with foil to prevent the crust from browning too much.
When cooked, rest for 10 minutes covered with foil. Carve and serve with light spring vegetables of choice.
Recipe by The Red Bistro at https://theredbistro.com/2013/03/27/spring-lamb-roasted-in-pistachio-rocket-crust/