Step 1Combine the pork, yellow onion, green onions, diced water chestnuts and egg in a bowl. Season with a little salt or soy sauce.
Step 2Starting with 1 wrapper, place about 2 tablespoons of the pork filling down the center of the wrapper in a "log" shape, about 1 inch from the edges. Start rolling the wrapper up from the short end, then fold in the sides and finish rolling. Repeat with the remaining wrappers until all the filling has been used up.
Step 3Heat 1 inch of oil in a deep skillet over medium-low heat and fry the egg rolls, in batches if necessary, until golden brown, about 8 to 10 minutes.