Preheat the oven to 220°C/fan 200°C/gas mark 7. Pull the leaves off the cauliflower and cut the core out of the bottom. Bring a large pan of water to the boil and add the cauliflower. Cook for 5 minutes, or until beginning to soften. Drain and leave to steam dry for a further 5 minutes.
Whisk together 2 tbsp oil, the coriander, cumin, turmeric and cinnamon. Place the cauliflower in a large round oven dish, big enough to later take the lentils. Generously rub the cauliflower all over with the spice and oil mix and season to taste. Place in the preheated oven and roast uncovered for 20 minutes.
Meanwhile, add the remaining olive oil and the shallots to a medium frying pan over a medium heat and fry for 7-10 minutes, until the shallots begin to turn golden brown and caramelised. Add the garlic, sumac and apricots and cook for a further 2 minutes. Stir through the lentils and stock and season to taste.
Remove the cauliflower from the oven and spoon the lentils and shallots around. Return the cauliflower to the oven for a further 20-30 minutes or until tender.
Once the lentils are cooked, squeeze the lemon juice over the top. Scatter the cauliflower and lentils with the toasted almonds, pomegranate seeds, parsley and mint. Serve the cauliflower sliced into chunky wedges.