i'm sure someone is already doing it but free video game idea:
roguelike styled after dungeon meshi
go into dungeon, find different recipes and shit, return to hub, dungeon remakes itself in meantime.
you can only go so far on each run based on your food supplies. new recipes let you make new food stuffs out of the monsters you encounter, which lets you extend your food supplies. there's a lot of ways you can go with this.