Question [Q] How to tftp boot kernel , NFS mount rootfs for android phones

Dear Geeks:

Is it possible to test kernel/rootfs without reflashing my android phone except rooting and installing recovery/bootloader ?
If yes, how? A step-by-step instruction will be extremely appreciated.

BTW, as a thank you,
a beer will go to the first one offering such an instruction working for LG optimus 2X.

Thank you all.

James