Preheat oven to 400°F (200°C). Spread cauliflower florets on a baking sheet, toss with olive oil, salt, and pepper. Roast 25 minutes, until golden and crisp.
While cauliflower roasts, whisk together tahini, lemon juice, maple syrup, garlic, and water until smooth and pourable. Season with salt.
Transfer roasted cauliflower to a serving bowl. Drizzle with tahini dressing, sprinkle with pomegranate seeds and parsley. Toss gently to coat.
Serve warm or at room temperature.