"hiraNya SrAddham" - HS for short - (not srartham, incidentally) means 'doing SrAddham with hiraNyam or gold, instead of the traditional method of doing a homa, feeding the two brAhmaNas chosen and invited for the SrAddham, offering the piNDa to the deceased parent or forefather, etc. It can be done by anyone. The word 'hiraNya SrAddham' was likely coined when gold or gold coins were the currency, or else, gold piece might have been offered as dakShiNA to the brAhmaNas in those days, but the correct position is not known.
About 40 or 50 years ago, tabras used to resort to HS when the convenience for doing a pucca SrAddha were not available, and, in the case of many tabras then, money was the main problem. Hence, even while inviting the two brAhmaNas, it was customary to make it clear that it would be a HS and not a pucca SrAddha. After the SrAddha rite was over, the brAhmaNas used to be served with coffee and uLundu vaDai; it was believed (and is so written in the smritis) that uLundu or black gram is tantamount to meat and that pitrus require meat for their complete satisfaction! The dakShiNA was slightly more than what the priests used to charge for a pucca SrAddha (with vEShTi + angavastram, full meals) and if my memory serves me right, my father used to offer Rs.2/= to each brAhmaNa, way back in the 1950's.
The contours of HS have also undergone many changes in the intervening period. Whatever your priest or vAdhyAr in Bharuch says will be the final word.