Rinse the split peas and soak in a large bowl of cold water for at least 6 hours.

Preheat the oven to 200°C/Fan 180°C/Gas Mark 6.

Line a large baking sheet with baking paper.

Arrange the aubergine wedges on the prepared baking sheet.

Pour 4 tablespoons of vegetable oil into a small bowl and use a pastry brush to coat each side of the aubergine before sprinkling them with ½ teaspoon salt.

Roast for 25 minutes, or until completely soft and cooked through. Set aside.

Meanwhile, heat 3 tablespoons vegetable oil in a large saucepan over medium heat.

Add the onions and cook for 15 minutes, stirring occasionally, until brown and soft.

Add the garlic and cook for a few minutes, adding a bit more oil or water if the pan has dried out.

Toast the cumin and coriander seeds in a small pan over medium heat for 1 or 2 minutes, stirring a few times, until fragrant.

Transfer to a mortar and pestle or spice grinder and grind.

Add the spices to the onions, along with the turmeric, cinnamon, white pepper, and chilli flakes and stir well.

Drain the split peas and add to the onions, along with 500ml of the just-boiled water.

Bring to the boil, using a spoon to remove any scum that rises to the surface.

Cover and cook over medium heat for 15 minutes.

Add the stock, tomato purée, and 1 teaspoon salt.

Pierce each dried lime with a fork a few times and add these to the pot along with the lemon juice.

Grind the saffron and sugar in a mortar and pestle.

Add 2 tablespoons just-boiled water and let steep for 5 minutes, then add to the stew.

Cover and simmer until the split peas are completely cooked and soft.

Once the split peas are cooked, gently stir in the aubergine.

Cook for 5 minutes to bring everything together.

Taste and adjust the seasoning to your preference.

Just before serving, top the stew with the fried potatoes, if using.