Rodipet unfortunately only make one Syrian appropriate food, since all the others are low in protein. It could in theory be fixed with extra protein in the diet, but since many hamster owners would likely either want to avoid the complicated math or don't feel confident enough with having to balance a diet the mix I've linked works out very well.
That diet:
https://www.rodipet.co.uk/pet-foods/...che=1575487607
I would avoid making entire mixes on your own. It isn't a very straight forward process and you can do endless harm providing an unbalanced diet, and not all damage unbalanced diets cause can be reversed. In the UK you're especially blessed with a balanced, biologically appropriate, and even better yet organic mix, which gives even more incentive to not take an unnecessary risk!
If you really want to make nice things for your hamster, consider making treat mixes instead out of whole high quality seeds, nuts, etc. This won't cause a dietary imbalance if fed in reasonable amounts however it gives you the very important opportunity to even further increase the dietary diversity of your hamster. You can pinpoint safe ingredients that would be beneficial to add which aren't included in the main diet, while being able to avoid adding ingredients which are already in the main mix(as these won't add any dietary diversity and therefore would not be very beneficial in comparison).