A few things I really cannot stand:
-- Offal (I know its trendy to not waste food now but it's still got vile textures and is usually far to strong for me).
-- Marzipan
-- Fennel and anything else that tastes of aniseed
-- Celery (I really don't understand why this appears to often in restaurants - its got a fairly distinctive taste so I doubt it's super popular. maybe its the "zero calories" trend?)
-- Coconut (why oh why does every decent-sounding restaurant dessert have to include it?)
-- Olives (so many times as a kid I was caught out thinking they were grapes and so many times as an adult I am upset because everyone who likes them gets to scoff before dinner arrive at every Italian restaurant)
-- Feta (texture and taste all wrong)
-- DILL - I hate dill with a passion. It's fur. Green, smelly fur. Not only is it disgusting, but it turns up unexpectedly in anything that involves salmon (rarely is it mentioned on menus that they are going to spread a layer of the revolting stuff all over a lovely piece of fish) and, the cardinal sin, it's almost impossible to pick it all off!!