Buy laying pellets in bulk from your local farm wholesaling store. They are usually cheaper than supermarket bought feed.
Grow silver beet in your garden or a deep pot. It can be picked daily and fed to your chickens (see Chickens love silverbeet).
Keep a bucket of laying pellets topped up a all times in your chicken enclosure. You may be wary of your chickens gorging themselves on their feed, and yes they will eat a lot. But they know when to stop, and this will keep your hens laying regularly. As soon as they go a few days without feed their natural instincts tell them to stop laying, for the survival of any offspring would be a risk.
Any leftover food scraps can be fed to your chickens.