Pretty sure no amount of participation in cooking can make children start liking food with specific tastes, like eggplants or celery. If they like it - great! I they don't like it, but parents do - well, _that_ kind of home-cooked food will never be liked.

(Unless you process them so much, and add so many spices, that they no longer have any original taste.. but by that point they are at "pre-packaged" level of cooking)