Pick through the lentils to remove any small stones that might still be present. Put the lentils in a saucepan of cold water. Bring to the boil and cook for 10 minutes, then drain.
Meanwhile, preheat a grill (broiler) to high and line a large baking sheet with foil. Lightly brush the eggplant with oil, season well with sea salt and freshly ground black pepper and grill for 5 minutes eac