If he likes milk he might like yogurt? I've read on hear that it is good for them (Timber won't eat it). The link I posted earlier for the Higgins mix that you cook has some type of rice and I know Timber likes that. Here's another link with interesting recipes... http://www.einsteinparrot.com/kitchen/recipes/
I feel your pain because Timber is picky too. I just keep sticking it all in there. Eventually, he will stick his beak in most things. I can tell pretty quickly when he is really disgusted by something (as he is by yogurt). I give him a little scrambled egg every morning. I just whisk the egg with a fork and microwave it (20 sec, stir, 20 sec, stir and check to be sure liquid is gone). I give him a teaspoon full with his breakfast and put the rest in the fridge in a sealed container for the next day. He does usually eat that. I've also found that he likes meat, just about any kind of meat. Chicken is probably his least favorite, though he does like a chicken wing bone. I know some here don't agree with feeding meat, but Timber is underweight. My vet told me to feed him meat if he wants it, just to avoid fatty cuts.
Wish I could help more, but I'm not very experienced myself! What I like about the forum is being able to hear what everyone else does. I've picked up many useful things that way.