My standards are White foods. Mashed potato, rice, pasta, eggs, custard, pudding, fish, mac and cheese.
As for the fish - Catfish will keep after cooking and reheat well for several days so you don't have to keep going to the store. Plus it is a very mild flavor.
I marinate it for about 30 minutes in equal parts butter, olive oil and lemon juice, with some garlic, basil, oregano, salt and pepper (amounts will be dependant upon how much fish you are making but for about a pound and a half of fish use about 1/4 cup of each liquid and 1sp of each seasoning) then just grill or bake on a rack till done. I also use this marinade on chicken, pork and lamb. But for a flare, its fish all the way
I've posted this before, but I have found this cookbook invaluble. Cooking well for the Unwell, by Eileen Behan. It has multiple sections with recipes for just about every diet situation we might ever encounter. When I have been in flares and just plain tired of eating the same food over and over, I have gotten ideas of ways to change things up. I actually went and got a second copy of this book because I was always loaning it out and didn't have it when I wanted it. You can get used copies on amazon really cheaply. It just has so many ideas about ways to incorporate extra nutrition into low residue and clear liquids as well as smoothie recipes. I just really think its great.