1. Preheat the oven to 200°C, fan 180°C, gas 6.
2. Tip the lentils, chopped tomatoes, 3 tbsp harissa, and sweet potatoes into a large, ovenproof pan set over a medium heat. Bring to the boil, stirring occasionally, then season to taste.
3. Top with the cauliflower florets, nestling them into the tomato sauce.
4. Mix 1 tbsp oil with the remaining 1 tbsp harissa and brush over the tops of the cauliflower. Roast in the oven for 30-40 mins until the cauliflower and sweet potatoes have softened.
5. Meanwhile, toss the smaller and more tender cauliflower leaves in the remaining 1 tbsp oil and spread out on a baking tray. Season with freshly ground black pepper and roast in the oven for 8-10 mins, tossing occasionally, until lightly charred and softened.
6. Serve the cauliflower with a side of roasted leaves.
Tip: Simply halve the ingredients and follow the same method if serving 2.
See more 5-ingredient recipes