Sounds like the (chicken) child is running the household.
Its a beautiful plate, but its not a healthy plate for chickens. The rest of the treats you've assembled may by comforting in thought, but the practice is "poor". However happy the chicken appears, science does not support the offered diet.
Add me to the list of those recommending a complete commercial feed, such as a name brand "All Flock" or "Flock Raiser" with free choice oyster shell on the side and treats (if you must) not to exceed 10% by weight of the total diet. Scratch, btw, is a treat. Also, find a new vet for your poultry.
I'm sure that feeding commercial feed to your chicken, when they want treats, feels no better than giving a twice daily shot to a beloved pet, but when the shot is insulin and the pet has diabetes, you are doing it for their own good. Likewise with the commercial feed - its not the tastiest thing in the offering, but its for their health that you do so.
Finally, and I may be misjudging, but I suspect that even if you take the advice of the experienced posters responding in this thread, you are likely to buy some whole grain non-GMO Organic feed blend. First, you want at least 18% protein, try to avoid the soy-free varieties unless you must for some allergy/dietary reason (soy has certain amino acids not easily obtained from other grains), and second, serve it to the bird either fermented, or as a wet mash of oatmeal-like consistency. Why??? Because all those whole grain feeds are incomplete, of themselves - the manufacturers add vitamin powders to complete the diet - powders picky chickens will gladly disregard while hunting out their favorite seeds. Getting the feed wet first makes it MUCH harder for them to be as selective in their eating, helping to ensure they take their vitamins.