Preheat oven to 170°C.
Spray roasting dish with low calorie cooking spray then sprinkle half the sliced onion, 2 bay leaves, some of the fresh rosemary and oregano, some of the tomato slices, both potatoes, a couple of slices of lemon and half the garlic in the roasting tray.
Place the leg of lamb on the top.
Spray with some more low calorie cooking spray and place the rest of the ingredients on top.
Pour the juice of a lemon all over the meat.
Season well and sprinkle the smoked paprika over the top.
Wrap the tray in foil and ensure it is well sealed. Now place in your preheated oven for about 5 hours.
After 5 hours, turn the oven up to 200°C and leave the meat to sit for 20 minutes.
After 20 minutes, remove the foil and remove some of the juices and potatoes from under the lamb.
Run the juices through a fat separator and blitz to make a gravy. Return the meat to the oven to crispen up (not burn!)
Remove the meat from the oven, shred with a couple of forks and place in a serving dish. Pour over some of the gravy over and serve.