Zucchini Babaghanouj

Broil zucchini about 6 inches from heat source, turning occasionally, until completely blackened, 25 to 30 minutes. Scoop out flesh (discard skins), and drain over a fine mesh sieve, pressing to release liquid, about 10 minutes. Pulse flesh in food processor with garlic, tahini, lemon zest and juice, and 3/4 teaspoon salt. Season with pepper. With machine running, slowly stream in oil. Cover and refrigerate until cold, at least 30 minutes and up to 1 day. Serve, drizzled with oil and sprinkled with more zest and freshly ground pepper.