hi, sounds like it's snack food that's the challenge. I sympathise, we hve the same no-go list, except for the bananas. Fruits are limited as we are also kinda keeping an eye on salicylates. My kid is coming to 3. He is not a fussy eater and in fact, I always say the irony is that he loves to eat but he can't eat so many things.
For now, this is what we do for snacks:
- mini chicken drumsticks
- meatballs
- roasted potatos
- rice cakes (plain or with honey)
- home-cooked chickpeas (put in a paper cone)
- occasional fruits
- occasional sorbet treats
- roasted gram (only gram and salt)
- carrot/celery sticks
I use potato starch as a binder and it also gives a light translucent crust. Our main seasoning is himalayan salt (keeping off everything marine-related on advice of a doc and mother who btdt), spring onions, some garlic and onions. Check your cooking oil to make sure it's on the ok list. I was a dodo and did my GF/Corn-free/seed-free cooking in a corn oil, and then later in a canola/sunflower oil the first few weeks we started on this.
I am currently experimenting with making rice burger, japanese inspired. First attempt kinda fell apart (literally, hahaha), but still edible. There's hope yet...
Basically use the freshest ingredients you can find. I cook everyday now (watching amines too, just in case) but keep things simple.
And I second everyone who says GF flour mixes sometimes just get too complicated. I really stocked up on the GF pre-mixes, thinking I'm just gonna take it by the horns and bake every week, but the kid's symptons got worse

- and really, do I have to go through all that exotica ingredients to see if he's also reacting to those?? Fava bean flour? Xanthan gum? Tapioca starch?Teff flour? In the end it's really just easier to go back to basics.
(btw, you can make chicken nugget-like nuggets *hahahaa* either by pounding chicken fillet to tenderise, coating with potato starch and frying, or by running pre-cooked chicken through the blender with some cooked potato, potato starch, salt, herbs and a bit of stock. Coat with potato starch and rice flour and fry.)
(and, another challenge is sauces. No ketchup/mayo what do we do?? We've settled for soups, stews, flavoured oils and a big cup of water/rice milk at the side.)
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