1. Rinse the split peas and soak them in cold water for 1 hour. Drain and place in a heavy-based saucepan with turmeric, garlic, and salt.
2. Pour in stock and bring to a boil. Reduce heat, cover, and simmer gently for 1 hour, or until almost all liquid is absorbed.

For the Soup

1. Cut each aubergine into thirds widthways, then slice each piece into wedges.
2. Heat oil in a deep frying pan and fry the aubergine in batches over medium heat (approximately 350°F/177°C) for 10 minutes until golden. Transfer to a plate lined with kitchen paper.
3. Return all aubergine to the pan, increase heat, add garlic, and fry for 2 minutes.
4. Add cumin seeds and fry for 1 minute. Add tomato purée and harissa to taste and fry for 2 minutes.
5. Pour in stock (be careful, it will bubble), and cook for 3–4 minutes until most of the liquid is absorbed.
6. Remove from heat and stir in vinegar.
7. Thinly slice the fennel and toss with salt in a bowl.
8. Massage the fennel for 1 minute until it softens slightly, then add lemon juice.
9. Pour the cooked split peas into a liquidizer, add olive oil, and blend to a smooth purée. Add water if needed.
10. Pour the purée into a clean pan and set aside.

To serve

1. Gently reheat the split pea purée, divide between warmed bowls, spoon over the spicy aubergine, and top with fennel.