Combine all ingredients, except the last two, together in a big bowl. Mix well using the hand. Set aside, covered, for at least 30 minutes.
Separate the wrappers carefully one by one. Cover the separated wrappers in between a clean, damp kitchen or paper towel to prevent them from drying out.
In a small bowl, mix together 1 tablespoon of flour and ¼ cup water. This will be used to seal the wrapper together.
To assemble, place a wrapper on a flat surface, one of the pointed corner facing you. Spoon about a tablespoon of the filling on top of wrapper across the bottom part. Fold the bottom corner over the filling. Then fold both the side corners over the center to close the sides. Roll the filled portion over until the other end of the wrapper. Dip your index finger in the slurry and pat it on the remaining corner to close and seal the spring roll completely.
Heat oil in a deep fryer or deep pan over medium heat. It should be high enough to cover the spring rolls. Make sure the oil hot before adding the lumpia. Try not to overcrowd the pan so it will cook evenly.
Deep fry on medium heat for 5-7 minutes or until golden brown.
Drain oil from the spring rolls by placing them on a plate lined with paper towels.
Serve while hot and crispy with chili sauce or ketchup as dip.
Notes
Best served with sweet chili sauce or banana ketchup.