Melt the shortening in a large wide pot over medium heat. Working in batches, add the beef and cook until browned on all sides, about 5 minutes. Transfer to a colander to drain, then rinse with water and return to the pot.
Add the beef broth, chicken broth, tomato sauce, prunes, 10 cups water and Spice Group 1 to the pot. Bring to a boil, then reduce the heat to medium and cook, stirring occasionally, until the meat is tender, about 2 1/2 hours.
Stir in Spice Group 2 and cook 15 minutes, then stir in Spice Group 3 and cook 15 more minutes. Season with salt and add Tabasco sauce to taste.