What can be used safely (e.g. basalt "hot stones") to fill volume of shallow pan for deep frying? I have an electric hot pot that would be good for deep frying as it automatically controls heat. However, the pot itself is more of a pan - shallow and wide. I was thinking of things I could put in the pan (on one side) in order to:


Increase the depth of oil (on other side)
Decrease the volume of actual oil used
Retain heat


So far, my questionably "best" idea/hack is to use basalt "hot stones" typical of massage therapy.

Seems like basalt is used in some cooking forms, e.g. as a hot plate for steaks etc. Some sub-questions to go along with this idea:


Can basalt stones withstand deep frying conditions of 375F?
Are most basalt stone products pretty much the "same" kind of basalt?
Is it safe for cooking (e.g. leeching, chemicals, reaction to hot oil etc.)
Are there any other safety issues I'm neglecting?


If people have any other ideas that can answer the question I'm all ears.

Electric "hot-pot" and "hot-stone" reference:
It's a neat idea and basalt is definitely a solid at 1000°C and is only a fluid liquid at 1200°C, so it's quite safe except it takes more time to heat up basalt than oil...  So the oil you're going to save while using a large pan containing basalt is going to be offset by the extra energy you need to pump into the system.¹


On a camping site when you don't have enough oil? Yeah, go for it!
In your own kitchen? Up to you, but I would just buy a smaller pan.


Note¹: Basalt is volcanic rock and also takes more time to cool down, so be careful when you do use it; leave the pan overnight on your counter to allow the basalt to cool off...