Hi, it can be really difficult. My little one is wheat, dairy, rice and soya free but there are a few things that you can try (in addition to the loads of really great suggestions from everyone else). Potatoes, polenta- which I cook up and spread into a pan and slice into "bread". Corn pasta-available on line but if your little one can eat rice then sainsbury's and most of the other shops also have this in their "free from" range. I try and avoid most gluten free processed foods because of the soya and rice problem. Hummus, pate (some of waitrose's own brand are good-but be careful and check all ingredients). Peanut butter (if no nut allergy)
Bob's red mill does some cake and bread mixes and a great pancake mix you might want to try. I blend vegies and mix with the pancake mix for savoury or you can use fruit for sweet.
Sainsburys and Tesco both do a gluten free porridge oat (porridge is gluten free but if your child is highly sensitive they may react to the cross-contamination as regular oats may be processed in a site where other things are processed).
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Flours/grains-holland and barrett, whole foods, health food stores-buckwheat, potato, corn, almond (asuming no nut allergy); juwar/sorghum, millet . good website--
http://www.foodsubs.com/Flournw.html. corn crackers (instead or rice ones etc)
Please feel free to get in touch if you want more help or just to chat, it can be really difficult and frustrating at times especially in the beginning. Good Luck!!
Please feel free to get in touch