Warm your oven to 200°C/Fan 180°C/Gas 6. Trim the aubergines and cut them into small chunks. Peel the onions and thinly slice them. Cut the tomatoes into wedges. Peel and thinly slice the garlic. Add the aubergines, onions, tomatoes and garlic to a large roasting tin. Pour over 2 tbsp olive oil and scatter over 2 tsp turmeric, 1 tsp cacao nibs and a pinch or 2 of cayenne pepper (cayenne is spicy, so use as much or little as you prefer). Add a pinch of salt and pepper and toss together. Slide the veg into the oven to roast for 20 mins.
Drain and rinse the chickpeas and shake them dry. Strip the kale leaves off their cores. Shred the leaves. Fill and boil your kettle.
When the veg have roasted for 20 mins, add the chickpeas to the roasting tin. Pour over the passata. Add 750ml boiling water and stir. Return the roasting tin to the oven for 25 mins.
After 25 mins, remove the tin from the oven and fold through the kale. Return to the oven for 5 mins to wilt the kale. Taste the sauce and add more salt, pepper or cayenne pepper if you think it needs it. Ladle the tray bake into warm bowls and serve.