o make the filling: In a large mixing bowl, combine the ground chicken, carrot, onion, garlic, scallions, salt, black pepper, oyster sauce, and 1 egg. Mix until evenly combined.
To prepare the pastry bag: Place a pastry bag inside a tall glass and fold the opening over the rim. Spoon the chicken filling into the bag, secure the top, and cut off the tip.
To assemble the lumpia: Place a spring roll wrapper on your work surface in a diamond shape, with one corner pointing toward you. Pipe an even horizontal line of filling across the wrapper. Fold the bottom corner over the filling, followed by the left and right corners. Roll tightly until only the top edge remains. Beat the remaining egg, brush it over the edge, and finish rolling to seal. Repeat with the remaining filling and wrappers.
To fry the lumpia: Heat the cooking oil in a large pot to 325°F (163°C). Working in small batches, fry the lumpia for about 5 minutes, turning occasionally, until golden and crispy and the chicken is completely cooked through. Transfer to a paper towel-lined plate or wire rack to drain. Repeat with the remaining lumpia.
To serve: Serve immediately with sweet chili sauce or your favorite dipping sauce.