That sort of LED die can be cooled with a chipset cooler or similar - 5cm square heat sink with 12V fan cooling -
fan can run from the raw 12V nicely. You will need good solid mounting with thermal-paste to transfer that
amount of heat well. LEDs must be kept cool - cooler than silicon devices I believe, so don't skimp on cooling.
The device is probably three 3W chips in series, it will probably pull about 10V at 0.85A, so a constant-current drive
running from 12V would work. Offhand the CAT4101 driver might be a good match - check the datasheet though.
I've seen 4-chip 12W LEDs in a similar format wired as 2-in-series-in-parallel.