Place the pork and chicken in a 1 1/2 gallon stock pot with enough water to cover. Cook at a medium simmer for 2 hours, or until the meat is very tender, skimming occasionally. Remove the meat to a bowl and reserve the stock. Meanwhile, in a separate large stockpot, do the same to the beef. Remove the beef and discard the broth.
Place the potatoes in a medium saucepan, cover with water and simmer until tender.
Remove and discard the bones and skin from all of the cooked meat, pull apart or cut into chunks and process in a food processor or meat grinder until ground. Put 2 pints of the reserved pork and chicken stock into a 1 1/2 gallon stock pot, reserve the rest for another use. Add the ground meats to the stock. Dissolve the black pepper and the cayenne pepper in 1 tablespoon water, and add to the stew.
Add to the onion and tomato to the food processor, process well and add it to the meat mixture with the ketchup and Worcestershire sauce. Process in the food processor the cooked potatoes, then add to the stew, stirring until any lumps are removed. Stir in the salt. At this point, the stew should be soupy not watery. If the stew is too thick to stir easily with a flat spatula or pancake turner, thin it slightly with more reserved pork and chicken stock. Cook for 30 minutes, stirring constantly.
Puree and add the corn, then continue to cook the stew over very low heat for 1 hour, stirring often and scraping the bottom of the stock pot with a flat spatula or pancake turner to avoid scorching.
Recipe adapted from Georgia Cooking in an Oklahoma Kitchen by Trisha Yearwood (c) Clarkson Potter 2008