Sauté the onion in oil, add the tomato puree, the vegetables finely chopped, and enough water to fill half of the saucepan you are using.
Put the nukides along with the meat into the saucepan, and allow them to cook over medium heat for about 2 hours, adding water from time to time so that the nukides and the meat do not dry out, and stirring frequently to prevent everything from sticking to the bottom of the pan.