When we cook Pancit Molo at home, we tend to make the filling before and in big batches for practicality. But it won't only end as part of the Pancit Molo soup but can made into other dishes as well.
There are three basic ingredients we use in making this filling aside from the ground meat and additional spices.
Minced garlic. We peel and mince "tons" of garlic to give it both an aroma and the flavour needed.
Kusay. Even though we grow some in the backyard, we usually buy a few bundles then finely chop it. Not to be confused withy kinchay, kutsay (as it is called up north) is like chives but not hollow. It is also referred to as sibuyas na mura.
Tahure. As far as I know this is soy bean curd "soaked" in soy sauce and salt. We often get it from the wet market by the cube.
To make the filling we simply mix all these then add some seasoning like pepper, garlic and onion powder, additional salt if needed. Then we simply fry a small portion of the mixture for taste test and make some necessary adjustments after. When done, we wrap them in plastic and in small batches so as to preserve the whole mixture when we only use a small portion.
Molo wrapper. These days, one doesn't have to go through all the hassles since they are readily available in the grocery. A good Molo wrapper is thick and doesn't easily break so as to preserve the Molo balls when serve. Back in Manila, when I used to make Pancit Molo in the office (almost everybody even stayed late that time when the "news" broke out-lol) I had to content with using "sio mai" wrapper I got in the grocery since I can't find a good quality wrapper. 
Mostly, when not used in Molo soup, it often ends up as fried patties or "sahog" vegetable dishes.