Prepare the marinade. In a bowl, rub the chopped garlic with salt, add a little lemon juice, honey, molasses and olive oil. Mix everything thoroughly until a thick paste is formed. Pierce the meat all over with a needle. Line a large baking dish with baking foil, place the meat on it and brush it all over with the marinade.
Cover the baking dish with the lid and refrigerate it with the meat for 12 hours. Preheat the oven to 180 degrees. Remove the meat from the fridge after marinating and leave it to stand until it reaches room temperature. Then cover the meat with a 'tent' of baking foil and place the baking dish in the oven. Reduce the temperature to 140 degrees and bake slowly for 5 to 6 hours. Occasionally baste the meat with a little lemon juice. When the meat can be separated from the bone with a fork, the lamb is properly cooked. You can prepare a dip by mixing white yoghurt with grated garlic.