I give my guy any leaf lettuce, any fresh herb, kale or chard or collard greens, and also things like endive/chicory or celery cut up in small pieces.
Also, radish or carrot tops are great. As are dandelions (leaf and stem), assuming they’re pesticide-free.

Do try to space out the greens high in oxalates or calcium (lots of easy reference lists on the webs for those).

I spent two months away from my bun while he was doing immigration home quarantine and I was finishing a work contract halfway around the world. I came back and he had gone from skin and bones after his extremely long flight and drive (24+ hours) to a plump little dumpling. Found out my dad had fed him a barley biscuit PLUS lots of fruit every single day (my written instructions were “an occasional treat”). His reason: “He’s happy to see me.” This was on top of his pebbles and salad.

My guy just recently rediscovered baby spinach after a three year hiatus. Silly buns.

@Q8bunny – Lol – (His reason: “He’s happy to see me.”) Dads and instructions…..

Pfff… never trust doting grandparents to uphold routine and discipline.