Oh dear that does limit things. Not sure if it's the nuts that are a problem but mixerama would be another option if the ingredients are ok. Just not really heard many reviews or tried them myself.
(This has peanuts)
https://www.mixerama.de/fertigmischu...ter-extra?c=46
https://www.mixerama.de/fertigmischu...oldrausch?c=46
(Supposedly for long haired hams)
https://www.mixerama.de/fertigmischu...-mischung?c=46
Another possibility - rodipet, it's the new organic one so again not heard much about it. This is the junior one.
https://www.rodipet.co.uk/pet-foods/...nior-500g.html
There is also the bunny hamsterdream expert on zooplus but it does look like a lot of small seeds for a Syrian.