Protein for Tween

Thanks for responding to my last-night's post:

Crabby: He'd just started to like popcorn shrimp when we had to discontinue because of the wheat (flour) coating, and I haven't found gluten-free/soy-free/corn-free substitute yet.

Miz: Most of Morning Star Farms items are made with soy and wheat and some with corn, which he can't have.

HLV: The Herbalife protein powder is based on soy, which he can't have and also has maltodextrin which is a gluten-no-no product.

Emmett: I saw quinoa on that list which is a grain but very high in protein so I think I'll add that to his diet... thanks!

Are there any more ideas?

This is hard, isn't it? Soy is in almost everything, but when he eats that or cashews or some of these other things, he turns from my sweet helpful loving son into Evil Child.