Let your steak come to room temp. Too cold and the middle wont cook. Get your skillet up to med-hi heat. Drop a tablespoon or so of your favorite fat, around here, that would most likely be coconut oil, I like bacon fat myself. Kosher salt and fresh cracked pepper on one side, that side goes down in the pan, while that side is cooking, season the other side. Cooking time will vary depending upon thickness and how you like it. I tend to go about 5 minutes a side. Honestly thats it. Heat, salt, pepper, any more than that, and you are disrespecting the meat. There is of course a place for wet rubs, marinades, braising, etc, but that is for tougher, lesser cuts of meat.

As you do it, you will find there are a couple of variables. As I stated earlier, thickness of the meat and how you like it, but also your stove and what "med-hi" means on your might be different from mine. Too hot and your outside is burnt before your inside is done. Too low and you never get that nice salty/peppery crust on it, and its all kinda gray and rubbery. Just like anything else in life, these are guidelines, now get out there and get to it!

Enjoy!

Great answer wheelhouse. Simple is best. Room temperature critical. A couple of tweaks that I sometimes employ:

• Saute in slightly browned grass-fed butter.
• A quick sear on both sides then pan and meat into a 350 degree oven for a few minutes to finish up. GF beef likes a little more TLC than your average commodity cut.
• Rest the meat before eating. Resting allows the proteins to slow their action and re-absorb some of the moisture in the meat. No rest = red liquid on plate.
• While resting, add a little more butter or fat to the pan with a splash of homemade stock or red wine (I know...not paleo) and scrape any beefy goodness stuck to the pan. Reduce, pour over steak and eat.
• Serve with a smear of paleo bernaise or herbed GF butter.

Man...this is making me hungry.

Afterthought - you asked about cooking times. I personally don't cook by time, but use either temperature or "doneness". If I'm in a geeky mood, I use my digi thermometre. Mostly I use the hand-test method (see below).

http://www.meninaprons.net/2006/01/learning_doneness_the_hand_tes.html

All good ideas - just a couple more thoughts. As your steak is sitting on the counter to come to room temp, salt it amd gently pat salt into steak. Wait for one hour, then cook. After about 15 minutes the salt draws water to the surface, but then a bit later the steak reabsorbs it, taking all the salty, watery goodness with it. One hour salting is key.

If you have a steak that is 2" thick or more, you will have a hard time pan-frying it because by the time the steak is done in the middle a dark gray ring will form between the cooked, red layer in the middle and the fried outer layer. Gray ring is bad, unpleasant, untasty.

For those steaks, put them in a pan, preferably cast iron, though stainless will work. Preheat oven to about 170 degrees. Put steaks in oven and heat to internal temp of about 95. Then put on stovetop and cook to desired temp. Frying from about 95 degrees instead of 40-60 helps eliminate the gray ring, but still lets you get the char on the stovetop if you want it.

These are both Cooks Illustrated tricks, BTW.

I like this Thai marinade for sirloin:

• 1 tablespoon tamari or coconut aminos
• 1/2 teaspoon freshly ground pepper
• 2 scallions, cut into 1-inch pieces
• Zest of 1 lime
• 3 tablespoons lime juice
• 1-1/2 tablespoons fish sauce
• 1/2 teaspoon palm sugar, optional
• 1/4 teaspoon crushed red pepper
• fresh or dried mint, to taste

Sear the sirloin on both sides. Mix together the marinade ingredients. Let the steak rest a few minutes, slice it thinly, and toss it with the marinade. Let it sit at least an hour before eating, overnight is even better.

I cook all my lamb in a cast-iron skillet and I must say that I prefer to cook it slowly at low heat. Seems less carcinogenic and the meat is so succulent and delicious. I keep it simple and just use clarified pasture butter, salt, and pepper.

Just wondering... you have seasoned your new cast iron skillet?