This is what works for me. I use the terra cotta plates that you can get at the garden center. They are heavy and can't be turned over. I wet the crumbles and mash them into the plates. I have a little waste but the chickens clean that up. Plus they are really cheap to buy.
I have several different sizes so I can use them with the chicks right on up to adults.
I have several different sizes so I can use them with the chicks right on up to adults.