Cut the tomatoes into large pieces. Deseed and dice all the peppers. Heat olive oil in a medium size pot. The flavor belongs in the recipe, so use a good amount of it. Add the onion and garlic, and before it is brown, add the cumin. When the cumin is blended, add the tomatoes and peppers, the tomato concentrate, and the harissa. Add salt. Blend the ingredients with a long spoon. Add 1 - 3 bay leaves, and the thyme.