Boil 2 pounds sliced russets 5 minutes. Toss with 1/4 cup olive oil and 1 tablespoon chopped rosemary. Grill the potatoes, 1/2 lemon and 1 sliced red onion. Chop the potatoes and onion; toss with olive oil, parsley, salt, and juice from the grilled lemon. Toss with grape tomatoes and grilled zucchini and eggplant.