Update baba ghanoush for Halloween by making the smoky eggplant dip as dark as night—with black tahini. Serve with homemade grissini "snakes."
Preheat broiler. Place eggplant on a foil-lined rimmed baking sheet and broil, turning occasionally, until soft and blistered all over, 15 minutes. Let cool 20 minutes, then cut open lengthwise and scoop out flesh into a fine-mesh sieve set over a bowl; press with a spatula to remove excess liquid.
Add eggplant to the bowl of a food processor with garlic, tahini, lemon juice, and 1 1/4 teaspoons salt. Process until smooth, 30 seconds. Drizzle in oil; pulse until combined.
Transfer mixture to a serving dish. Stir 2 teaspoons water into yogurt; drizzle over dip. Sprinkle with cayenne and red-pepper flakes. Serve with grissini or chips.