I hav a Mai Pham cookbook. Though I don't honestly use it, I bought it because she makes a decent curry.
Her egg roll recipe isn't too great (IMO), but that's just me. A lot of times I think that Asian restauranters and cook book authors deviate from "authentic" recipes. Why, not sure...but that's what I've noticed about Vietnamese recipes.
The problem with cooking your pork first that you will get cooked meat crumbles. Think back to biting into an egg roll at a Vietnamese resturant, the meat never falls out this is cuz it's rolled raw and cooked.
The recipe below looks ok. If it were me, I would ditch the chicken and replace it with shrimp. I'd also ditch the bean spouts. Never seen bean sprouts in a Vietnamese egg roll. (Ms. Pham, what were you thinking???
)You are also missing what I call the filler. Most recipes will have taro or jiciama in them.
On the green onions, try using just the green part. Cut it into long pieces (the length of your roll). Spread your meat on the paper, put the green onion in and then roll it. A little way to make it fancy or "kick it up".
Also, once you have assembled all of your filling, take a tiny little spoonful and cook it on a frying pan. This will allow you to adjust your seasoning as needed.
p.s. this is all stuff I would do for an authentic egg roll. If you're not looking for authenic, and just want to experiment, by all means add whatever sounds good.