Heat a few spoonfulls of oil in a large pot. Add the meat and fry it until it is browned but not done. Reduce heat. Add water, salt, and pepper and simmer for about half an hour.
Add the tomatoes and onions and contine to simmer until the meat is done and becoming tender.
Remove some of the liquid and mix it with the peanut butter to make a smooth sauce. Add this to the meat-tomato-onion mixture.
Continue to simmer on very low heat until the meat is very tender.
