In the bottom of a bowl large enough to hold the lamb, combine the rosemary, oregano, cinnamon, salt, pepper, garlic, lemon zest, lemon juice and olive oil and stir to combine well.
Add the lamb chunks, and toss to coat all over with the olive oil marinade
Cover and place in the refrigerator for at least 3 hours, preferably overnight.
About an hour before you put the lamb in the oven, remove it from fridge and let stand at room temperature
Preheat the oven to 300F/150C
While lamb is resting, cut 2 strips of parchment paper about 2 ½ feet long. Place them on the counter or on a baking sheet at right angles to each other.
Remove the lamb from its bowl and set aside on a plate for the time being, leaving remaining marinade and juices behind.
Add potatoes, onions, peppers and cherry tomatoes to the bowl and toss with the remaining lamb marinade.
Transfer the vegetables to the center of the parchment paper
Place the lamb on top, and add a bayleaf. Add two whole garlic cloves, and juice of 1 lemon over the top. Toss the empty lemon shells in with the lamb
Bring the edges of the parchment together and fold up tightly, and tie together with a length of butchers twine.
Place in oven and cook for 4 hours
After 4 hours, raise the temperature in the oven to 390F/200C and cook for another 20 minutes to help ensure the lamb and veggies are browned
Remove from the oven. And let rest for 30 mins before serving.