Peel, wash, and dice the potatoes in bite sized pieces. Put enough oil in the bottom of a medium sized non-stick skillet to cover the bottom of the pan, and be about 1/4 inch deep. Heat oil over medium high heat until hot. You can check the temperature by dropping a piece of potato into the oil. If the piece of potato sizzles, you are ready to add the rest of the potatoes and onions. After you add the vegetables to the hot oil, generously salt and pepper them, cover with a splatter screen, if desired, and let them fry for about 10 minutes. Gently turn the potatoes over, and let them fry for about another 10 minutes. Be careful not to turn the potatoes too often, or they will begin to disolve. Continue frying and turning until the potatoes reach desired doneness. I like to have a plate lined with a paper towel ready to take them up on. This allows the excess oil to drain off of the vegetables. Add salt and pepper to taste after removing from the skillet, and serve hot.