Trim top and bottom from eggplant.Cut into cubes and set in a colander. Toss cubes with a little salt and let drain for 15 minutes.Rinse well and pat dry with a paper towel.Slice the white and light green parts of the leek.Heat olive oil in a large skillet over medium heat. Saute leek until soft, 3-4 minutes.Add rinsed eggplant to skillet. Saute until soft, 5-15 minutes.Add olives, capers, nuts and red pepper flakes. Heat through.Toss with drained pasta, adding small amounts of additional olive oil if desired.Top each serving with grated cheese.