if its the same acahar we are talking of which we get in most of the traditional newari momo pasal:

do everything as usual: onions , all the masalas, can / fresh tomato cook them together like we usually do to make golveda ko achar...then grind it in mixture with cilantro...

Then u can add bhatmas and mix it in mixture  to make it like traditional momo soup..but its hard job..fry the bhatmas take the cover out..thts gonna take a long time...so u can instead use teel or sunflower seed...wont be as good as with bhatmas but still testy...

Hope it helps