I feed our flock their regular 16% layer feed, but I supplement their diet with fresh fruits, veggies, herbs, peanut butter, honey, really anything healthy except citrus fruits, raw potatoes, and tomato. Citrus fruits have too many conflicting articles to be worth the risk with so many other viable options available, and potatoes and tomatoes are fine so long as they're cooked or contain no green spots if raw
I also treat my babies to fruit-filled waffles a couple of times per month, but moreso in the colder months when there is less to forage for. Here's what I put in the food processor in any given day, mixed with some scratch and black oil sunflower seeds:
Apples
Carrots
Spinach
Watermelon
Cantaloupe
Pineapple
Kiwi
All sorts of berries
Squash
Yams
Zucchini
Brussel sprouts
Any combination of 3-4 above and if I'm feeling saucy, I'll drop a whopping dollup of peanut butter or honey. I always add cinnamon and oregano, but I also give them, ginger, thyme, cilantro, or dill. I get creative and I have fun giving them the best of what I can give them.