If using leftover fried rice, ensure it's not too wet. If needed, add a little soy sauce to enhance flavor.
If using frozen spring roll wrappers, let them thaw completely. Keep them covered with a damp cloth to prevent drying out.
Place a spoonful of fried rice in the center of a spring roll wrapper. Be careful not to overfill to avoid tearing.
Fold the bottom of the wrapper over the filling, then fold in the sides and roll it tightly. Seal the edge with a bit of the beaten egg to hold it together.
Continue filling and rolling all the wrappers with the fried rice until you have several spring rolls ready to fry.
Heat oil in a pan over medium heat. Fry the spring rolls until they are golden brown and crispy on all sides, about 3-4 minutes.
Remove the spring rolls from the oil and drain them on paper towels. Serve hot with your favorite dipping sauce.