Place The lamb in a large roasting dish that would fit easily in your fridge. Using a sharp knife, make slits all over the lamb.
Using a high powered blender (I used my Nutri Ninja) blitz togther the wild garlic, rosemary, anchovies, lemon and oil. If the mixture is a little thick, add a bit more oil.
Add salt and pepper to taste, bearing in mind that you might not need much salt because anchovies are pretty salty.