Place saffron and 2 tbsp hot water into a bowl and set aside to steep. Combine cauliflower florets, saffron water, olive oil, coriander, cumin, salt and pepper to taste in a large bowl and toss together until cauliflower is evenly coated. Transfer to a large baking tray and place into oven for 10 minutes.
Heat a large frypan or flat grill pan over a high heat. Remove cauliflower from oven transfer to heated pan and cook until browned, turning occasionally, about 6 - 7 minutes. Remove from heat, drizzle with olive oil, season to taste and toss well to coat the cauliflower. Set aside until needed.
Place 100g of the hazelnuts in a small saucepan with milk, bring to the boil, then simmer until soft, about 15-17. Transfer hazelnuts and milk into a blender and process, gradually adding cream, until a smooth purée is formed. Transfer to a small bowl, season with salt, pepper and lemon juice. Set aside until needed.
Heat oil in a small saucepan to 180C.
Fry drained capers until crisp and lightly golden, about 3 - 4 minutes. Drain on paper towel and set aside until needed.
Place the raisins, brandy, sherry vinegar and sugar in a small saucepan over medium heat and bring to the boil. Remove from heat and set aside until needed.
Cut the flesh and remove pith from the preserved lemon. Finely dice the preserved lemon rind and combine with yoghurt, lemon juice, sumac and salt. Set aside until needed.
Pick the leaves from the parsley and mint and place in a large bowl. Drizzle over the olive oil, lemon juice, salt and pepper and toss well to coat the leaves.
Roughly chop remaining hazelnuts and set aside until needed.
To serve, spread hazelnut purée over the base of platter, drizzle with olive oil. Sprinkle raisins and half of the chopped hazelnuts on to the purée, then pile roast cauliflower on top. Drizzle with preserved lemon yoghurt then sprinkle with raisins, remaining chopped hazelnuts, crispy capers, and grapes. Finish with the parsley and mint.