My 25mo toddler is rejecting all kinds of greens and very picky with food. When she is much younger, we cook porridge with fish/chicken/smash vegs now shes getting older, we bring her out for meal and she basically just refused to eat greens! Any advice anyone?

Oh do not worry! This is something that many parents face. I agree with what Sonika suggested. I would either decorate them into fun shapes so that they enjoy eating them as is. Or if they are too fussed about the particular food item, hide it in various recipes as a mash or paste. Make sure you do not strain such pastes to avoid losing the nutrients. I find soups the best way to hide food along with mixed Pizza (with a dosa base instead)