There is a cooking technique called "Blackened", which is used on meat or fish. It's perfect for bison meat. Bison or buffalo is really lean meat, so this technique is perfect.
Buy any type of Cajun, Creole or Blackening Spice mix. Put oil over the steak, cover with spice mixture and put on hot grill.
As soon as the spices darken - the steak is ready. I prefer my buffalo medium rare. it is to lean to be cooked more, because it will become chewy.
Enjoy. I did !!!!