to get 12% alc from a 1101 wort youre going to have to get down to an FG of 1013 so this would necessitate some sugar. i would try something like pils malt base with some caramunich III and a bit of cara-aroma, mashed at low temp, and 15% white sugar or so, with a powerful fermenting yeast like 3787/WLP530. probably fermented cool with a spell of cold conditioning as well to smooth it out, cause this isn't an estery beer. 20IBUs or so of whatever neutralish hop you have to hand.
anyway those are my meandering thoughts on the topic