Is it allowed for my 11-year-old son, who recently reverted to Islam, to eat non-Halal chicken in our remote Irish town where Halal options are scarce and costly and also because he has dietary restrictions due to allergies?
Bismihi ta'āla
If he is still non-baligh, non-mukallaf, he can eat it, but I would definitely not recommend such a thing. We believe that non-halal food has a deep impact on the human spirit and mind, and even physical impact. Try to find alternatives for him, without compromising, and instill in him the importance of halal food, and sacrifices a Muslim makes for the sake of his/her religion and obedience to Almighty God who put all these laws and rulings for reasons that will benefit us.
And Allah knows best