The only thing that is fixed in the can is Awajishima onions, but you can freely add seasonings and ingredients to the base recipe! You can put ingredients you bought in Awajishima (fish, meat, vegetables, anything is OK), seal the lid, sterilize, and attach a label of your own choosing, all by yourself, making your own original, one-of-a-kind can. It's perfect as a souvenir, and can be used as room decor after you've enjoyed the contents.