Begin by lighting 1 bag of charcoal in the center of the spit. Coals will become red hot in about 30 minutes.
While the coals are heating, prepare the basting mixture. Juice 8 lemons and add juice to a large bowl. Set aside.
To the bowl of a food processor or blender add 1/2 of the fresh rosemary, parsley, basil, and 2 heads of garlic. Process until the ingredients form a paste.
Using a whisk, mix the herb paste into the fresh lemon juice. To the bowl add 1 cup wine, 1 cup olive oil and the bottle of balsamic vinaigrette salad dressing. This will be the basting sauce.
Submerge the remaining fresh herbs in the basting sauce and set aside.
Line a table or large work surface with the plastic trash bags.
Place the lamb on its side on the table. Slice the remaining 2 lemons in half and use the halves to rub lamb with lemon inside and out. (Used Lemon rinds will go in the lamb for roasting). Brush one side with olive oil.
Liberally season with sea salt, freshly ground black pepper, and dried oregano, rosemary, and parsley.
Using the tip of the paring knife, make small incisions every few inches in the skin and insert slices of slivered garlic.
Flip the lamb over to the other side and repeat the process.
Brush the inside of the lamb with olive oil and season liberally with sea salt and freshly ground black pepper.
Skewer and secure the lamb on the spit. (Using two "U" clamps or passing two wires around the skewer and exiting the back of the lamb prevents the lamb from spinning during turning.)
Fill the cavity of the lamb with the marinated herbs (save a few rosemary sprigs for basting), remaining garlic, and squeezed lemon rinds. Stuff the cavity with bread slices.
Pour the remaining wine over the bread slices and stitch the cavity closed with twine.
Wash hands well and use disinfecting wipes to wipe down all surfaces, seasoning bottles, etc.
Distribute the coals under the lamb so that there are four piles, two on either side of the lamb at the shoulders and hind legs. Two thirds of the coals should be distributed by the hind quarters.
Place the lamb at the level closest to the coals. Turn on the rotisserie. Tie a slip knot and allow the twine to wrap itself around the skewer binding the lamb tightly to the skewer. Secure with a knot and cook at this level for 30 minutes.
After 30 minutes, raise the lamb to a higher level and begin basting every 15 minutes so that the skin always appears moist.
Add charcoal 6 - 8 briquettes at a time to each pile throughout the cooking process. Ignite the hardwoods and then place smoking wood under the lamb in a grill area where there is no charcoal. Try to keep a steady stream of smoke.
To determine whether you need to add more coals you can gauge the temperature of the coals by holding hand over the coals at the level of the lamb and counting 1-one thousand, 2-one thousand, etc. You should be able to count to at least 6-one thousand before you need to add more coals but not more than 8-one thousand.
The lamb can be lowered back down toward the coals after about 3 hours of roasting or when a meat thermometer registers 145 degrees F (63 C). The total grilling time should be 4 - 5 hours.
Remove lamb from coals when leg/shoulder meat temperature registers 170 degrees F (77 C). If you prefer your lamb medium rare, you can remove the lamb at 155 degrees F (68 C). Allow the lamb to rest for 15 minutes before carving.