Oh gosh, I'm sorry.
Did he get fluids and all that good stuff?
Pain meds, anti-nausea?
I'd say just pick something low fat like chicken and rice, but I'm doing that with fish and rice with Ellie now and she isn't doing too well on it. I don't like to recommend rx diets needlessly, but in this case, it may be best until you can get a balanced recipe. After one episode, the pancreas gets angry so easily and I don't want to recommend a combination of ingredient, even temporarily, because it's just too serious of an issue.
Hoping somebody else has an idea though...