+1
I love this technique. It's called reverse sear. I use 1.5-2.0" thick rib eye or strip steak. Put it in a 250-degree oven on a rack. After about 40-45 minutes, it reaches an internal temperature of 120-125 degrees. I let it rest about 5 minutes and then sear for 1 minute on each side in a smoking hot cast iron skillet with very little oil. ...
I've taken this to the next level recently - a cheap sous-vide like method for steaks and a rack-of-lamb (near $0 actually, assuming you have a cooler, and a thermometer with a long wire probe helps, and a blow torch for the final step, but you can use a fry pan). We will be doing more of this soon.
For 1 1/2" thick steaks - Fill a cooler ~ 2/3 of the way with 132F tap water (add a little boiling water if needed). Put the steak in a zip-lock bag with a little olive oil and rosemary and garlic. Dip the bag in the water to push out the air, then seal it. You might want to clip the bag to hold it just above the water. Close the cooler, and cover it with towels (coolers aren't usually insulated well on the top, they are designed for, wait for it.... cool foods, not warm - so the towels provide insulation for the top).
Leave it sit in the water bath for about 90 minutes, you can go longer, up to ~ 3 hours and it makes no difference. Top up with a few cups of boiling water from time to time as needed to keep the temperature at 127-129F (so far, I only need to top up a few times during the first 40 minutes, as the meat absorbs the heat).
Take the steaks out, put them on a rack over a sheet pan, and hit them with the blow torch to sear. I have a MAPP gas torch which gives a hotter flame than propane. Just takes a few minutes to crisp them, and they are cooked to perfection (for us - medium rare) inside. And it makes a LOT LESS smoke than a hot fry-pan sear. Adjust the water bath temperature just a few degrees up/down for your liking.
The steaks and the rack of lamb were awesome (I just broiled the lamb really close to the burner to finish it). Enter 'sous-vide' and DIY or cooler into your favorite search engine, and you'll find tons of info.
This has a lot in common with all-grain beer brewing (except for the torch!), so it seems natural for me. BTW, 'sous-vide' actually means 'under vacuum' (or something like that), as it was common to vacuum seal the food before putting into the water bath. But to me, the water bath is more important than the sealing method, but I guess 'bain-marie' was already taken.
-ERD50