I'm in the transitional phase between liquid and mushy food, so far i've tried scrambled egg, a sloppy 1 egg cheese omellete and a small bowl of very loose ready brek. All have been ok so far, no side effects or issues with it passing through.
You could also try big soups, spag bol, shepheards pie, fish pie (as suggested) cheesy mash, baked beans, fish in parsley sauce.
Good luck and happy experiementing