What can I feed my toddlers that is healthy and good for them etc?

I have tried many foods out over their lifetime, but they seem to have gone off a lot now, and they are so fussy, they don't like to try new things. I want some healthy options. My 4 year old daughter won't eat any vegetables or fruit and hasn't done so for 2 years now, that is how fussy she is and she won't eat meat or fish (apart from chicken dippers, chicken nuggets, sausages) On her sandwiches she had chocolate spread, she won't eat anything else, or try it. She won't eat salad foods or eggs. My boys are not quite so picky and are willing to try new things if they look appetising. Please help me out, i'm at my wits end with their eating habits. Any recipes or food ideas will be handy and of great use, thanks