Add the olive oil & onion to a large pan and heat to a medium heat. Fry for approx 8-10 minutes until soft and browning.
Add in the garlic, spices and stir for another few minutes, then add in the chopped mushrooms and red peppers and fry for 2-3 minutes.
Add the walnuts to a pan and fry toast until lightly toasted. Allow to cool a little, then add them along with the carrots and sun-dried tomatoes to a food processor and blitz to a chunky crumb.
Add the walnut mix to the pan, along with the tomatoes, lentils, water, harissa, balsamic and tamari.
Simmer for 25 minutes.
Season with salt, pepper