There is only one certainty! Your bird will die without food and water! Give as much variety as your wallet can afford and do not consistently feed the same foods, except pellets and seed treats. To the pellets and/or seed you can add variety. Some species are picky and variety is limited. The foods listed will give you a basic idea of the variety you can offer. He may have eaten some of these already, but it will be a rarity if your bird eats all the foods listed. Scrambled or hard-boiled eggs, cooked lean meats and seafood, thawed frozen vegetables or fruits (or canned). Fresh fruits and veggies washed first. Endive, spinach, kale, cooked yams/beans/rice/beets, cornbread, wheat bread, crackers, unsweetened dry cereals, pizza, spaghetti, macaroni, corn and peas, etc.
Just like humans, your bird will not like all foods, but keep trying to introduce new ones. NO avocado, NO chocolate, NO liquid with caffeine in it (pop, coffee, tea) and no dairy products.. Oil, salt and sweets are not good for your bird. Unhealthy food curtails longevity, damages organs and threatens the immune system. Use a separate dish for fresh food so you can remove it after a couple hours as moist food rapidly grows mold and bacteria.
Freeze leftovers; mix cooked rice and veggies together and place in ice cube tray, then into a freezer bag for fast food, (feed thawed)
Hookbills do not need grit.
One last reminder, your bird must have food and water on a daily basis to survive. Fresh food and water prevents bacteria buildup.