Question on frozen fish, please read!

My SO is in the process of being diagnosed with diverticulitis and he can't eat a lot of things now, no dairy, no meat, no nuts, no pasta, no fried food, he basically can't eat anything so we're trying to find things he can eat except salads! Fish is okay but I had a question about the already beer batter frozen fish you buy at the store, is that fish already fried? We can bake it in the oven but he wouldn't eat it because he doesn't know if the fish was fried before it was packaged and frozen. We're trying to find actual foods for him to eat other than eggs, raw veggies, fruit, and salad. Because he just wants an actual meal!! He loves fish and I know we can do the regular baked fish but I just wanted to know if the battered fish is fried before it's packaged and frozen. This has been a huge change for us and if anyone who has dealt with diverticulitis, any meal ideas? Or anything else we should know medically, he can't go back to the doctor until his new insurance kicks in February 1st, so as of now we're just kind of lost on what to do until he can actually get in to see a specialist.