Presoak the clay pot, top and bottom, in water for 15 minutes.
Make slits in the leg of lamb with a sharp knife and insert the slivers of garlic.
Mix the oregano, salt and pepper and rub over the lamb.
Insert a meat thermometer, away from the bone, and place the lamb in the pot.
Mix the wine and lemon juice and pour over the lamb.
Add the onions and green