Preheat the oven to 425°F (220°C).

In a large mixing bowl, combine olive oil, salt, and harissa, then toss in the cauliflower florets until well-coated.

Spread the seasoned cauliflower on a baking sheet in a single layer and roast for about 35 minutes, tossing halfway through.

Remove from the oven, stir in the remaining harissa, and roast for an additional 5 to 10 minutes until caramelized.

In a small bowl, whisk together remaining olive oil, tahini, honey, lemon juice, and black pepper to create the sauce.

Transfer the roasted cauliflower to a serving platter, drizzle with the tahini-honey sauce, and garnish with parsley and extra lemon juice.