Preheat the oven to 375 degrees. Lay the butterflied leg of lamb flat on a work surface, fat side down. Combine the bread crumbs, currants, pine nuts, parsley, garlic, feta cheese, olives, rosemary, olive oil, and lemon juice in a bowl and blend well to make a coarse stuffing for the lamb. Spread the stuffing evenly along the center of the inside of the leg of lamb. Fold the lamb towards the center, one side and then the other, to enclose the stuffing and form a roll. Pin the roll closed with toothpicks or skewers, or tie the roll in several places with butcher's twine so that it does not open during cooking.
Season the outside of the lamb with salt and pepper and place, seam-side-down, in a roasting pan. Place in the oven and roast for 45 minutes, then add the baby eggplants to the roasting pan with the lamb. Continue roasting the lamb and eggplant for another 35 to 40 minutes for medium rare.
Remove the lamb and eggplants from the oven and allow the roast to cool for 20 minutes before slicing. Serve 2 to 3 slices of lamb per person and 1 or 2 roasted eggplants. The eggplant should be left whole during roasting, then split down the middle to serve. They should be eaten by scooping out the creamy eggplant interior, leaving the shells behind.