I can't remember the make but J.S do a suet mix for dumplings ..You just mix it up ,roll it out spread with jam,wet edges roll up ,cover with cling and micro for 3/4 mins..
If you use syrup you will probably have to use a basin,grease it first then put syrup in the bottom then a ring of the suet pastry then more syrup ,then pastry etc finish with pastry..Not sure how long in micro for this might be trial and error,but it shouldn't take much longer than the jam roly poly..Leave the cling a bit loose to allow pastry to expand in both cases.Good luck