Combine all the filling ingredients in a mixing bowl: pechay, ground chicken, carrot, garlic, onion, black pepper, salt, egg and cornstarch.
Mix all the ingredients until well combined.
Lay a piece of lumpia wrapper on a clean flat surface. Put 2 Tbsp. of the pechay filling on top of the lumpia wrapper close to the edge towards you.
Roll the lumpia wrapper to wrap the filling and fold the sides when you are halfway then continue to roll until the other edge of the wrapper is closed.
Dab a little amount of cornstarch slurry or water on the edge of the lumpia wrapper to seal it.
Heat cooking oil in a frying pan and fry the lumpia until golden brown. Serve with sweet chili sauce or any of your favorite dipping sauce.