I'm not sure about cooked homemade diets TBH, hopefully someone will be along who can help you.
I know how frustrating it can be when you have a picky eater, but be careful how quickly and often you switch to another food. Before Bingley switched to raw he would turn his nose up at kibble quite often, and as he was so young and tiny I panicked and thought it would be an absolute disaster if he didn't eat a meal. Having moved on to raw now it's not so much of a problem, but we still get it occasionally. Bingley isn't so fond of certain NI flavours, and in the past (in his kibble days) I always reacted to his refusal so quickly and offered something he would eat. You have to be careful not to make a rod for your own back, as I think if we chop and change all the time they know if they refuse something it will be replaced by something else.
The other day he turned his nose up at his dinner, so after about 20 minutes I think I took it up and made no fuss. Put it down an hour and a half later and he ate it.
Have you tried hand feeding him a bit of the raw? Bingley wouldn't eat it out of a bowl immediately, i got some on my fingers and let him try it, then he would eat it happily.
Good luck whatever you decide to do