Heat 2 Tbs oil in an 8 qt pot over medium heat.
Add the beef stew meat and sear until browned.
Add the diced onion and sauté for 5 minutes.
Add the chopped carrots, celery, and garlic to the pot and let cook for a few minutes.
Add the rest of the ingredients, including the scored tomato, cut potatoes, cilantro, hot pepper (if using), hawaij, cumin, salt, black pepper, cayenne pepper (if using), and 6 cups of water.
Cover the pot with a lid and bring the soup to a boil.
Once the soup is boiling, lower the heat to medium-low and let it simmer for 3-4 hours.