With regard to the marvels of gravitational lensing
around black holes, why would you even need a hollow ring
to see your own back? It'd be there, just several million miles away.
Light can and will orbit a black hole: this happens at 1.5 times the Schwarzschild radius (the radius of the event horizon) and forms a sphere of light known as the photosphere.
So any light tangential to the photosphere will be trapped for eternity around the black hole, making it a fairly useful energy harvester, as this light is still outside the celestial censor that is the event horizon.
At this point, you whip your handy portable mass out of your multidimensional pockets (it could be anything, tame black hole, galaxy on a stick) and you wave it in a sorcerous fashion at the black hole.
Immediately (or close enough - I forget just how fast gravity waves, or gravitons or whatever, travel) radiation starts to peel off from the photosphere and sweep across the friendly vacuum towards your house, thanks to your precisely calculated actions.
As you smugly light your foot-long Havana cigar, the torrent of photons strikes the solar panels you installed on the roof of your house, and razes it to a mile-deep heat-glazed pit. You look around in case anyone saw that blunder.
Your oil-burning neighbour laughs like a drain.