Need to configure Oracle ASM to mirror accross 2 external storage arrays.

I am looking for instruction on how to configure Oracle ASM to be redundant across 2 direct attached storage arrays.

DB server design:
ASM is configured for a stand alone server...no rac or cluster.
The server has 2 direct attached SAS storage arrays.
Each external array is connected to its own HBA card in the server.

ASM design:
We want to have ASM be redundant across the 2 external arrays...the goal is to not lose the DB in case one of the arrays fails (for whatever reason).

Please please please do not suggest other designs. This design is locked in stone for the project I am working on and can't be changed.

I am looking only for instructions on how to make ASM be mirrored across the 2 external arrays.

Thanks in advance to any who post answers.
I am not a DBA, just a poor sysadmin who got stuck making this work.
Any help is greatly appreciated.