shelled peas that have been in boiling water for a minute and squised
cucumer slices (i take all the peel off)
Banana slices (but only leave in for 10 minutes max)
Goldfish also enjoy cooked and chopped up spinache- its very healthy for them as it is low sugar and high in minerals/vitamins. Pea's are also good for goldfishes digestion.
I feed all sorts of leafy greens to my goldies; many varieties of lettuce (not iceburg). They love baby spinach, and if it is boiled well enough to be tender, they'll chow down on kale, collard greens, and broccoli raab. They also enjoy orange slices w/ the rind and skin removed, cucumber, peas, etc.