Some vegies (excluding fruits, nuts, seeds and grains) that my birds eat include: cooked "mixed vegetables" from the supermarket freezer (corn kernels, peas and chopped up carrots) together with raw, chopped up bird's eye chillies and whole wolfberries=goji berries all mixed up in a food bowl; pumpkin (with the seeds) on a skewer, red capsicum (with the seeds) on a skewer, beetroot (not too frequently because of the oxalic acid) on a skewer, sweet potato on a skewer, broccoli on a skewer, various fresh, whole herbs including rosemary, basil, coriander=cilantro (with the roots) and kaffir lime leaves inside a baffle cage, various green leafy vegetables including watercress, bok choy, tong ho=a chinese green vegetable related to chrysanthemum, wolfberry greens=goji berry greens inside a baffle cage, washed and rinsed and reconstituted kombu seaweed=kelp (not too frequently because of high sodium and iodine and possible seawater contamination with arsenic as well as radioactive leakage off the Japanese coast) inside a baffle cage, certain edible mushrooms, cooked, including shiitake, porcini, morel (not too frequently because of hydrazines and formaldehydes) inside a foraging ball, sprouted corn and sprouted seed hidden inside gumnuts and cardboard compartments.
P.S. The reasons I choose to feed some of the problematic foods occasionally are that they also contain good nutrients, ie: beetroot has betalain, kombu seaweed=kelp has iodine and lots of other minerals and trace elements, and mushrooms have ergosterol.