I freaking love this dish! The mint magically turns into a savory herb during the rotisserie process and pairs perfectly with the rosemary and garlic. They somehow all combine to make the lamb a wonderfully mild meat which closely resembles roast beef.
In a bowl, combine the rosemary, mint, salt, pepper, olive oil, and garlic and mix well to combine. Pull the netting off the lamb, but do not discard. Open up the lamb and rub ½ of the mixture over the inside.
Close up the lamb and replace the netting to hold its shape and secure the herb-garlic mixture inside. Place the lamb on a baking sheet and rub the outside, and skewer lengthwise with a barbecue rotisserie rod. (If not cooking on a rotisserie, simply place on a baking rack in a baking pan.)
Place the rotisserie rod onto your barbecue rotisserie according to the manufacturer’s directions. Turn the rotisserie burner on high and turn on the rotisserie motor. Close the barbecue lid and cook until the internal temperature reaches 165 degrees for medium, about 2 hours. (Alternately, you can roast in the oven at 400 degrees for about 1 ½ hours.)
Remove the rod from the barbecue and the lamb. Let rest for at least 10 minutes prior to cutting. Once rested, cut the netting from the lamb with a pair of kitchen shears, then slice the lamb into thinly and serve.