boiled broccoli stems, just mush them in your finger, all my fish i've had have eaten that, because i only like the florettes...
Amazing gill what they eat. My fish out side in the pond got there first feed today since end of october. Just a sprinkle of wheat germSugar Puffs and Rice Krispies, had forgotten about them. My goldfish used to love Cornflakes as a snack.
Your fish is a savage!