Soak black fungus in warm water for about 20 minutes or until soft. If you're using shitake, soak in warm water a little bit too to wash them.
In your food processor, add 1/2 lb pork, 1/4 lb shrimp, 1 Tbsp tapioca/potato starch, 1/2 onion, 1/2 tsp salt, 1 Tbsp seasoning powder then start grinding them.
Transfer, cover and store mixture in fridge for 30 minutes to an hour.
Chop the remaining 1/4 lb shrimp.
Chop water-chestnut into small chunks.
Thinly slice black fungus/mushroom into long string.
Separate egg yolk and white, save half egg yolk for roll hemming. Beat egg white till fluffy.
In a mixable container, whipped egg white till fluffy.
Add chilled ground meat/shrimp, chopped shrimp, 1 Tbsp onion powder, water chestnut, black fungus/mushroom, 1/2 egg yolk, 1/2 tsp ground pepper and 1 Tbsp sesame oil to egg white container, beat them good until fully mixed.