Spring greens (not trying a shameless plug.. the first image didn't work lol)
And Asda definately do spring greens, wild rocket and watercress daily! (I work on that section so i know )
I also give ours mint, parsley, basil and chives occasionally. Never sage and spinach though i was told .
With Dandelions theres no problems growing your own especially at the moment, got an old tub in our garden and left it to do its own thing :2thumb: