
Stuff incisions with garlic, season, roast leg uncovered 30 min at 240°C/465°F (220°C fan). Lower to 180°C/350°F (160°C fan). Put everything else in pan, flip leg upside down, fill with hot water 1/4 way up, roast covered 3 1/2 hours. Flip lamb, roast covered another 2 1/2 hours, then brown uncovered 30 minutes. Strain pan juices, serve!
Preheat oven to 240°C/465°F (220°C fan-forced). (Note 2)
Garlic incisions - Use a small knife to make around 25 incisions all over the lamb, with most on the top. Cut around 6 cloves into slivers and stuff them into the incisions.
Season - Sprinkle the lamb generously all over with salt, pepper, paprika and garlic powder. Drizzle with olive oil and rub all over the lamb.
30 minute browning - Place the lamb in a roasting pan and roast for 30 minutes or until it has a nice brown crust.
Prepare for slow-roasting - Remove from the oven. Turn the oven down to 180°C/350°F (160°C fan-forced). Turn the lamb upside down. Pour / place all the remaining ingredients in the pan around the lamb (including remaining garlic cloves). Fill the roasting pan with hot water so it comes up about 1/4 - 1/3 of the way up the height of the lamb.
Slow roast part 1 (3 1/2 hours) - Cover with lid or with baking/parchment paper then 2 layers of foil. Roast for 3 1/2 hours. Top up water if it dries out (e.g. Might happen if your foil is loose) ** See Note 3 for larger/smaller leg roasting times **
Slow roast part 2 (2 1/2 hours) - Remove the roast from the oven and remove the lid/foil. Turn the lamb over so it is the right side up. Cover again and roast for a further 2 1/2 hours, or until you can pull meat apart easily with forks.
Finish browning - Remove cover and roast for a further 20 - 30 minutes (to brown).
Rest - Remove from the oven and transfer lamb to serving platter. Cover loosely with foil and rest for 30 - 40 minutes.
Sauce - Strain liquid into a clear jug. The fat will rise to the top. Scoop/pour most of it off and discard (I get 3/4 - 1 cup). There should be 2 - 3 cups of Sauce left. Adjust salt, pepper and lemon to taste.
Serve lamb with the Sauce on the side and Truly Crunchy Roast Potatoes* or Greek Lemon Potatoes. The lamb will stay warm enough for 1 hour so you can roast / prep other sides during this time.