Grind the walnuts with the onion, cumin, salt and red pepper paste and tomato paste in the food processor.
Soak the bread into water and squeeze the excess water.
Crumble the bread and add to the mixture in the food processor. Add the extra virgin olive oil and water and blend to make a smooth spread. If it appears to be too thick, add a little more olive oil.
Place the spread on a small salad plate or bowl. Pour the extra virgin olive oil all over and sprinkle with pul biber to serve.