Soak tree ears, set aside bean thread noodles. Chop pork to a finer consistency, put it in a bowl and add shrimp or crab, fish sauce, salt, pepper, garlic, onions and chives. Drain and dry the tree ears and add them. Add the bean thread noodles and blend thoroughly kneading with the hands.
Brush the rice paper on each side with the beer and set aside.
Cover with a cloth as you work. They take a minute or two to soften.
Put a heaping spoonful of the filling across the bottom third of the rice skin. Tuck away from you twice. Fold the sides over, then continue to roll. Seal with beaten egg and cornstarch. Fry in oil heated to about 350F until golden. Serve with lettuce leaves, garnishes and dip sauce.
This is from the "Art of Asian Cooking" by Bruce Cost. I was fortunate to have taken classes from him in Berkeley.