1Cut chicken thighs into small pieces and put into a large pot. Add the chicken stock, prunes and tomato paste. Bring just to a boil and then reduce the heat and simmer for 30 minutes.
2Add the rice, red onion, half of the chopped cilantro and half of the chopped parsley, and simmer for 15 minutes longer.
3Meanwhile, sprinkle the garlic cloves with a pinch of salt and chop them finely. Halve the peppers, removing the seeds, and chop the peppers finely as well. In a bowl combine the garlic and peppers with the walnuts and add the remaining chopped parsley and cilantro.
4Add about 1 cup of the hot soup broth to the chopped mixture and stir to combine. Stir the chopped mixture back into the simmering soup and add the coriander, mint, fenugreek and bay leaves. Simmer the soup for 10 minutes longer, then season with salt and pepper to taste.