Cook penne in a large pot of boiling salted water until al dente, as package label directs. Reserve 1/2 cup pasta cooking water, then drain pasta and return to pot.
Combine grilled vegetables, olives, tomatoes, basil, lemon zest, lemon juice and oil. Season with salt and pepper. Toss vegetables with pasta in pot, adding enough water to create a thin sauce. Divide among 4 plates, top with basil and serve.
