Soak the soya beans in water for at least 8 hours. Wash and place in the pressure cooker with water reaching 2 inches above the level of the beans, drizzle a few drops of oil and cook with the whistle on.

After 1 whistle, reduce the the flame to a minimum and cook for a further 20 minutes.

Once the steam has cooled, open the cooker, drain the beans and lightly mash with a fork. Leave to cool completely.

Wash and boil the barley in 3-4 times the quantity of water till the grains are cooked but remain slightly chewy.

Drain and leave to cool.

To cook the mushrooms, heat a tbsp of olive oil in a pan and add 1 chopped onion. Sauté till they soften. Now add the mushrooms and cook on medium heat till they are done and all the water has dried up. Season very lightly with salt.

In a large bowl or food processor, combine all the ingredients for the patty (except the oil) to get a sticky mixture.

Divide the mixture into 6 parts and weigh them so that each ball of mix is approximately 120g. Shape into patties and chill in the fridge for 2-3 hours.

Meanwhile make the sauce by whizzing the ingredients in a food processor. Add 1 tbsp of water at a time as and when required to loosen the mixture. The result should be a smooth, creamy, spreadable sauce. Store in an airtight container.

Once the patties have chilled, heat olive oil in a pan and let it get nice and hot. Fry the patties 3 minutes on each side on medium heat. They must have a golden crust.

To assemble the burger, lightly toast the halved buns in the same pan and slather generously with the cashew sauce. Place the patty on the bottom half, followed by sliced tomatoes, lettuce and cucumber slices. Top with the bun and serve.