Heat the oil in a large flameproof casserole or saucepan.

Then gently fry the onion and leeks for 10-15 mins until softened, stirring occasionally.

Add the garlic and cook for another 2 mins.

Stir in the ground coriander, cumin, chilli and cinnamon.

Cook for 2 mins, stirring occasionally.

Season with plenty of ground black pepper.

Add the chopped tomatoes, peppers, chickpeas, lentils, sweet potatoes.

Now add the orange peel and juice, half the nuts and 400ml/14fl oz water.

Bring to a simmer.

Cook for 15 mins, adding a splash of water if the stew looks too dry.

Stir occasionally until the potatoes are softened but not breaking apart.

Remove the pan from the heat and serve.

Garnish with coriander.