Coat the bottom of a large pot with oil and place over medium heat. Add the onion, celery, carrots, bell pepper, and garlic. Sauté for about 10 minutes, or until the veggies are tender. Add 5 cups of broth, diced tomatoes, tomato paste, thyme, oregano, red pepper flakes and bay leaf. Stir to fully dissolve the tomato paste. Add chickpeas and potato. Raise heat to high and bring to a simmer. Lower heat and allow to simmer until the potatoes are tender, about 20-25 minutes. Add up to an additional cup of broth if desired.

Remove the bay leaf and remove the pot from the heat. If you're using miso, ladle a bit of the broth into a small bowl and add the miso. Stir until the miso dissolves, then pour the mixture into the pot. Taste test and season with hot sauce, salt and pepper to taste. Serve.