for me worked very well cooked brown rice in association with vegetables. soaked for 24 hour and cooked. was ok in small quantities. some said they were ok with quinoa - small quantities. try them and try them combined with some fat,
I used to eat it with eggs and some mashed garlic. not much.
you should try to see with some enzymes maybe you also lack them.
at some point rice cake with butter worked ok. not more than 2-3 per day. i got bloeated but was better.
first I could eat them with butter but i couldnt stop my self from eating them. than i changed eating 1-2 of them with veggies dish togheter no butter was bettr. raw mashed garlic helped me a lot, and enzymes. not cured but helped.