Arguments for choosing bison over beef include the likelihood that bison is, on balance, better for you and is a meat from a once nearly extinct North American species whose prospects for survival are, perhaps ironically, enhanced by its homecoming as a food animal. Arguments against include cost (I paid about $29 per pound recently for some bison strip steaks) and, perhaps ironically, leanness, which complicates cooking. Still, when the numbers were crunched for the Labor Day weekend, the ayes had it.
Lean can mean tough and juiceless, especially if you're using a dry-heat cooking implement, like a charcoal grill. And on Labor Day weekend, would you be using anything else? As a precaution, I asked the butcher to leave a strip of fat on each steak; as an additional precaution, I pounded each piece lightly with a tenderizing mallet. And I used a marinade for Florentine-style grilled beef, from Bruce Aidells's invaluable The Complete Meat Cookbook (Houghton Mifflin, 2001). The marinade consists of a few tablespoons of extra-virgin olive oil, a teaspoon of kosher salt, some cracked black pepper, and some minced garlic, if you like. (I like.) You mix all that together in a broad dish, turn the pieces of meat in it until they're nicely slicked, and let the ensemble stand, covered, in the refrigerator for several hours or (better) overnight.
Holiday grillers, overcome by enthusiasm and beer, often lay fires that are much too hot. For boneless steaks and, for that matter, burgers a moderately hot fire is plenty. You are cooking food, not competing in an inferno Olympics. You know your fire is too hot if the food burns on the outside while remaining rawish inside. By this time, of course, it's too late.
My modest fire cooked the steaks in about five or six minutes per side and left nice grill marks too. The meat turned out to be a lovely medium rare, with each strip having a band of pink inside, deepening to rose toward the core. The texture was different from beef's: not the velvet butteriness of filet mignon but not tough either. More like a tri-tip. As for the flavor: superbeefy, I thought, without a hint of gaminess. Others at the table thought the meat had a flavor distinct from beef's but just as good. A veritable stampede of approval.