By licking the the methane ice walls, perhaps?
A thought…if there’s no Plutonian rock within practical reach of the surface, could I perhaps crash-land a small-ish asteroid into Pluto’s surface, and build the monestary into that?
Granted, I’d have to find a way of making the asteroid’s impact speed slow enough that it lands with more of a dull “crunch” than a catastrophic “ka-boom”…
Maybe you could use that to heat your monastary. 
Imagine… A moon too big to be real floating over your head. The sun is but a distant star no different from the rest. And all around you the flames dance and devour…
Sounds like the setup for a mystical experience to me.
Actually, even from Pluto, the Sun would be pretty bright. It would be about 1/1000th as bright as from Earth, but still roughly 100 times brighter than the full Moon.
Pluto and Charon went through a series of mutual eclipses not long ago, allowing maps to be made of the surface (check the link I mentioned above for more info). I can imagine how awesome that would be, to see the Sun as a barely resolved disk, still tremendously bright, passing nearer and nearer to Charon. Then, finally, going behind it, making a very shallow chord the first time, then cutting deeper behind it with every daily pass. What a sight, and you only get it every half-orbit, 125 years apart!