In a pot over medium heat, fry the onion in butter until it softens. Then add the garlic.
Add the beef, black pepper, mixed spices, and cinnamon. Stir until the beef turns brown.
Add the bell pepper and tomato paste, stirring constantly. Then pour in 4 cups of water, cover the pot, and let it cook for 30 minutes.
Add the oats and the remaining 2 cups of water. Let the soup boil for 2 minutes.
Pour the soup into bowls, garnish with parsley, and serve hot.