• 95 g (3¼ oz/½ cup) dried chickpeas, or 400 g (14 oz) tinned chickpeas
• 200 g (7 oz/1 cup) dried green mung beans (moong dhal)
• 150 ml (5 fl oz) olive oil
• 2 onions, finely chopped
• 4 garlic cloves, crushed
• 1 teaspoon dried red chilli pieces
• 6 ripe tomatoes, roughly chopped
• 1 tablespoon tomato paste (concentrated purée)
• 250 g (9 oz) Greek-style yoghurt
• 1 teaspoon chickpea flour (besan)
• 2 teaspoons crushed black peppercorns
• 50 g (1¾ oz) butter
• 150 g (5½ oz) oyster mushrooms, torn in half
• 1 Indian green chilli, chopped
• 3 tablespoons torn mint
• ¼ bunch of dill, leaves picked

If using dried chickpeas, soak them overnight in plenty of cold water.

Next day, soak the mung beans in cold water for 2 hours.

Drain the mung beans, and the dried chickpeas, if using. Place them in a saucepan with at least 2 litres (70 fl oz/8 cups) water and bring to the boil. Cook for about 30 minutes, or until they are tender. Remove from the heat and allow to cool in the liquid.

Heat the olive oil in a large heavy-based saucepan over medium heat. Add the onion and garlic and cook for a few minutes, stirring occasionally, until they start to brown. Add the chilli pieces and cook for a further 3 minutes.

Reduce the heat to low and stir in the tomatoes and tomato paste. Continue to cook, stirring occasionally, for about 10 minutes, or until the mixture becomes pulpy.

Add 500 ml (17 fl oz/2 cups) of the cooking liquid from the mung beans and 500 ml (17 fl oz/2 cups) fresh water, along with the mung beans and chickpeas (if using tinned chickpeas, drain and rinse them first). Bring to the boil, then reduce the heat and leave to simmer for 20 minutes.

Mix the yoghurt with a little bit of water to thin it, then stir in the chickpea flour; this will help stop the soup ‘splitting’.

Stirring continuously, slowly add the yoghurt to the soup. Turn off the heat, stir in the crushed peppercorns and season to taste with salt.

In a frying pan, melt the butter over medium heat. When it starts to froth, add the mushrooms and cook for a few minutes, until tender and soft. Stir in the green chilli, mint and dill, then season to taste.

Serve the soup immediately, with a spoonful of the mushrooms on top.