I have a collapsing colander. I put whatever needs to be washed in there abd sprinkle water over it outside.
Letting the water fall where it may.
In some campgrounds this is frowned on as 'grey water'. But I am very minimal. In an entire day of doing dishes and washing fruit and vegetables I don't think I spill more than a half gallon.
I used to cook dry beans a lot before the van thing.
It isn't terribly compatible unless you are on shore power and have an electric cooktop. Even then, having a bowl of beans soaking overnight sounds like a recipe for a wet foot. I've since converted to using canned beans. MOre convenient, and not as cheap.
Also, cooking beans is a pain to clean up. I try to avoid refried beans. That mucks up my small pot a lot. And I use the same one to make my coffee!
Cooking dry beans is even worse. You get that 'scum line' around the side of the pot.
That all said. I'm in the middle of working out how to put a simple sink in here.
First it's just going to be for campground water hookups. With a manual grey water thing under the sink that I have to take out and empty.
After I get that hooked up nice I'll get a freshwater tank and tie it all together. Hopefully in time for summer so I can more self contained for boondocking, or in town.