Help with food ingredients

Hi everyone first post here just looking for some advice.
My cockapoo buddy 8.5kg 16months old was forever hard work come feeding times not taking to anything tried on kibble alone (millies wolfheart) kibble/wet, cold press and also raw trying each for atleast a couple of months each. Some days only eating half his recommended some days not eating at all. For the last 10 weeks or so ive been cooking his food myself made up 70% beef mince and chicken breast and the rest carrot brocolli and sweet potato with great success eaten as soon as it goes down morning and evening but when reading various websites they all seem to advise only giving brocolli and sweet potato as an occasional treat. Should i swap them out or continue as i have been. No health issues or toilet issues whatsoever.
Thanks any help appreciated.

There are recipes on line for dog food as i know they have to have additional suppliments too or they will become ill, like humans do if we dont have the right nutrients .If you want a quick fix butter box do home made equireverlent if you have not got time to do all this preparation but he sounds like he loves your food so take a look on line things that must be added to keep him healthy.