Bison has very little fat, and can, like venison, be dry if overcooked and stringy if undercooked. I'd suggest cubing and stewing it, maybe in Guinness.

*Googles*

Aha!

That's funny, ej, I was just on the same site, looking at this recipe for a roast.

I did a bison roast for Thanksgiving, and here's what I learned the first time 'round:

-low and slow--about 50F less than for beef (I know 275F seems ridiculously low, but it's true)
-lots of liquid and a dutch oven with a tight-fitting lid
-The meat thermometer is your friend. Check it after the first 1/2 hour and fairly frequently after that. Since you have to open the lid to do it, might as well baste while you're in there.
-Slice thinly. My uncle carves roasts by the slab, and even though the roast turned out quite well (though done about an hour before expected), it would have been much tastier if he'd been a little less generous with the thickness. (I refuse to use the term 'mouthfeel' because it squicks me out, but that's kinda what I'm getting at.)
-The leftovers, if there are any, make a fabulous shepherd's pie.

Enjoy! It's very yummy if done right, and I know you've got the cooking chops to do it up proper and all.

Yeah, I was going to suggest braising, which does wonders for tougher meats.

(i pray this is as delicious as i imagine)

"Roast to 125F for rare, or 135F for medium rare."

Crikey, that's barely warmer than a bad fever!