Preheat your oven to 220°C (425°F) and line a baking sheet with parchment paper. Place the cauliflower florets in a large bowl with olive oil, salt, and black pepper. Toss thoroughly until every piece is coated.
Spread the cauliflower in a single layer on the prepared baking sheet. Roast for about 20 minutes until the edges start to brown. Increase the oven temperature slightly and roast for another 5 minutes to create extra caramelization.
While the cauliflower roasts, heat olive oil in a small frying pan over medium-low heat. Add the sliced onion and garlic and cook slowly until soft and lightly caramelized. Stir frequently to prevent burning.
Add the honey to the onion mixture and cook briefly until it becomes warm and glossy. Remove the pan from the heat and stir in the red wine vinegar and saffron. Mix until everything is evenly combined.
Transfer the roasted cauliflower to a serving bowl or platter. Pour the warm honey-onion dressing evenly over the top. Make sure the dressing coats as much of the cauliflower as possible.
Sprinkle the chili flakes and za’atar over the cauliflower. Scatter the grated halloumi and fresh parsley across the top. The halloumi adds a salty crunch that balances the sweetness perfectly.
Add a final drizzle of olive oil and a light sprinkle of salt and pepper. Toss gently if desired or serve as is for a beautiful presentation. Enjoy immediately while the cauliflower is still warm.