Sprouts. I hated them as a child and love them now.
weetabix i couldnt stand them you would pour the milk in and they would just go all soggy yuck! but now i love them i went to stay with my dad in ireland about 11 months ago and one day i just thought id try one of his and I did and i was like wow these are actually very nice i have them for breakfast most days now lol
roast beef--hated the dryness that was typical of roast beef those many years ago, but can't seem to get enough of it now
Green olives. I absolutely hated them the whole time I was growing up. However I created a Thanksgiving tradition for myself.....My Mom always served them because she, my Grandmother, and my Aunt loved them and I decided that I would eat one. I did this for years, each time hating it with a passion but proud that I had done something Id normally never do. Then one year when I was in my thirties I ate my annual "Thanksgiving olive"....and it was actually pretty good to me. Not a just gotten used to it kind of pretty good, but an honest to goodness "hey, this isnt half bad, I really like this" pretty good. Ive eaten them many times whenever they are available (or I just have a taste for them) ever since.
asparagus! i honestly remember my mom chasing me around the house and trying to force it between my teeth. "you didn't even try it!" "yes i did!" lol
Tomatoes! I still don't sit down at the table and eat a whole tomato, but I can enjoy a slice with some salt.