Preheat the oven to 350F. The first thing you will need to do is prepare the lamb. You will need to remove any outer packaging and then pierce the flesh with your knife making deep slits. This is so the marinade and seasoning will really rub into the leg of lamb.
Take the coarse spices and add them to a pestle and mortar. You will want to grind them up as much as you can. Then add these spices to a small bowl along with the salt, 1 tablespoon of lime juice, honey or maple syrup (whichever you are using), olive oil, mustard, and crushed garlic. Give all of these ingredients a good stir to ensure that they are combined together. This is your marinade for the leg of lamb.
Now take your aromatic mixture and rub it into the lamb leg on all sides. You can use your hands for this or a pastry brush if you prefer. Your hands will be the best tool as they can ensure that everything is covered. Set aside while you prepare the baking sheet and potatoes.
Rinse the potatoes and pat them dry. Cut slices into the potatoes about ¾ through. You can see in the pictures how they should look. Brush the sliced potatoes with the remaining marinade. Cover a baking tray with foil, and place on a rack with the potatoes and lamb's leg on top. Place the leg of lamb and potatoes into the oven.
Cook for 1 hour and 30 minutes. Turn off the oven and leave the dish for 10 minutes. This will give the meat time to rest.
Transfer the leg of lamb and potatoes to your serving plate and garnish with rosemary, lime, and berries. Serve at the table and enjoy!
Notes
Always make sure that you let the meat rest when it is removed from the oven. This helps the juices within the joint of meat to redistribute. If you try and carve straight away then it won’t taste as juicy or flavorsome. This is an important element.
Be careful when removing the lamb from the oven, it is a heavy piece of meat and it will certainly be hot.
It is best to use a bone-in leg of lamb rather than a boneless leg of lamb as it can help to keep the meat juicy and moist when cooking.