Deep, crackling crust, perfect medium-rare centered bison rib steak. Here's how to get there.
Step 1: Season it!
A day or two before you plan on eating, season the steak on all sides very generously with salt and pepper, then place it on a rack or a wooden cutting board in the fridge uncovered, flipping it once halfway through. Let it sit at least overnight and up to a day. The goal is to get the exterior very dry so that it'll sear up much faster (the biggest energy sink when searing meat is driving off surface moisture before it can begin browning).
Step 2: Ready to Cook
After a day in the fridge uncovered, the steak should look like this. You can cook it plain, but I like to add a few aromatics. In this case, some rosemary and thyme, and a few cloves of garlic.
Step 4: Hot Cast Iron
Heat a big cast iron pan over a high burner rotating it occasionally for about 5 to 10 minute. It should be smoking hot all over. Add a good amount of neutral oil (I used canola).
Step 5: Add the Steak
Carefully add the steak to the pan, laying it in gently so the hot oil doesn't splash. Also, turn off your smoke alarm. You won't be needing it now.
Step 6: Cook, Flipping
Cook the steak, flipping it every 30 seconds or so. This will help it cook more evenly internally, and don't worry, you'll still develop a perfect crust. (More on the science of that here.) The pan should stay ripping hot during this whole process. My IR thermometer puts it at above 600°F (315°C).
Step 8: Reduce Heat, add Butter and Aromatics
Now we enter the basting phase. Add the butter and your aromatics. Let that all melt.
Step 9: Pile and Baste
Pile the aromatics on top of the steak, then tilt the pan and repeatedly spoon the hot butter over the aromatics and meat. Reduce the heat if the butter starts to smoke excessively, which can happen.
Get in There!
The butter should brown and sizzle as it pours over the steak, but not burn or smoke excessively.
Step 10: Flip and Repeat
Flip the steak and take a second to admire the gorgeous crust you've created. Then keep basting.
Step 11: Use a Thermometer
As a home cook there is no more accurate way to check the doneness of a piece of meat than to use a thermometer. Don't try and be macho, just use one, it'll make your life much easier. This is a big steak and lean bison meat carries heat well, so you can count on about 10°F (5°C) of carryover cooking (that is, the steak will continue to rise in core temperature after you take it out of the pan), so pull it out at 115°F (46°C) for a nice medium rare. If you prefer rare or medium, that's 5 to 10°F (3 to 5°C) lower or higher respectively.
Step 12: Let it Rest
There's debate over the exact mechanics of what happens when a steak rests, but however it works, it helps keep your steak juicier when you eat it. And don't worry, we'll also deal with giving it a nice crackly crust later on! For now, put it on a rack and let it sit.
Step 14: Flip the Potatoes
Flip the potatoes when they get nice and golden brown and crisp. Continue cooking. They should crisp up just as your steak finished resting.
Step 15: Add Some Herbs
Chopped herbs, salt, and pepper are all they need.
Step 16: Rebuild that Crust
Your steak crust might have softened a little during resting. To rescue it, add a bit more butter to the now-empty potato pan and heat it over high heat until it just starts to smoke. Now pour that hot fat right back over the steak to get it sizzling again.
Bask in the glory of your little shaft of medium rare sunlight.