Cast iron pan followed by the oven is how I’d always done filet mignon before sous vide but you definitely don’t get edge to edge pink that way.
Sous vide and then searing in the cast iron pan is the only way to go.
Hi Newb and welcome back.
It’s good to know you are sticking with SV and doing so successfully.
For Filet Mignon there nothing wrong with the pre-sear and oven finish technique that a million restaurants use daily. It’s just a slightly different outcome that’s not quite as pretty.
Stay safe and keep well.
G’Day Mate. ( That is Australian for ‘Good Day’ or Hello to CharNoir ).
Damn you are good ! Your answers are brilliant, ( with a touch of humour ). The more I learn about Sous Vide, the more insightful your answers become.
How long have you been using SV ? I think it only became affordable or cost effective for home cooks, in the last 15 to 20 years. … I know you worked in the ‘food services industry’. Where did you get all your knowledge from, if you don’t mind me asking ?
Peter, Geelong, Australia.
G’Day fellow Newbie. This is one really good thread of questions and answers, that you have started. Thank-you for speaking up.
I wonder if my user name should be changed to ‘Newbie-July-2020’. I purchased two SV cookers, one week apart. ‘Anova Precision Cooker’ ( Immersion Circulator ) and ‘Gourmia GSV-900’ ( Water Oven ). I also purchased a Lodge cast iron frying pan, to do the searing of meat.
Thought I would ‘Add my 2 cents worth’ of knowledge, even though I am a beginner.
I see the ‘Sous Vide’ cooker as a new tool or style of cooking, that I can use in my kitchen. Something that gives a lot of control, for precise results.
I am thinking that Slow Cookers / Crock Pots are a good comparison to Sous Vide cooking. Both can have long cooking cycles.
Sous Vide - Advantage. Precise control of temperature. Wide range of cooking completion times. Uniform edge to edge ‘doneness’, with thicker items. All the flavour is sealed in the plastic bag, which can be used for gravy or soups. … AND, a tub of hot water leftover, to wash the dishes ! 
Sous Vide - Disadvantage. One temperature per Cooker. You want steak that is ‘Rare’, ‘Medium’, and GOD forbid ‘Well Done’ ; then get 3 machines. You want hot vegetables, then buy a 4th machine. … But wait, perhaps it is an ‘Advantage’, because the chef/cook can say ‘Tough’, everyone must have ‘Medium Rare’. LOL ! 
Slow Cooker - Advantage. Allows the recipe to be tweaked, along the way. Open lid and do a taste test. ( I only use my slow cooker for stews and casseroles. )
NOTE : “Moisture is the Arch Enemy of Crispy”, when it comes to the putting the crust on the meat. Dry your cooked Sous Vide meat, before searing. ( A lesson I learnt from my own mistakes. )
P.S. My FIRST cook was 2 inch thick ‘Eye Fillet Steak’. How could I possibly make any mistakes ? For added pressure onto myself ; I got my two meat lover BBQ expert brothers to be my taste testers. Both steaks ‘Medium Rare’. One cooked in cast iron fry pan and the other got the ‘Sous Vide’ treatment. … Sous Vide, the clear winner !!!
"You want hot vegetables, then buy a 4th machine. … "
Not necessarily.
For vegetables (such as butter poached fingerling potatos), I’ve been using a pot of water on the stove.
I found, using an instant read thermometer, that a setting of 5 out of 10 on the stove burner gets me a steady 185 F water temp in the pot.
It’s kind of like having two precision cookers, with one maybe not being quite as precise but for potatos, it doesn’t really need to be that precise.
As chatnoir mentioned in an earlier post, for different levels of doneness you could cook the medium first, then reduce the temp quickly (ice ?), and then cook the med-rare. You won’t be overcooking the medium while it’s sitting in the bath at a lower temperature.
Great reply. I was kind of joking about 4 machines, as a way of highlighting the specific temperature feature of Sous Vide cooking.
Thinking Outside the Box. You have done well, by showing how SV can be manipulated for different food types / temperatures. Using a pot of boiling water, and a thermometer, for your potatoes. Your own pseudo SV cooker.
Dare I say, you don’t need to use SV for every part of the meal.
Keep an Open Mind, and Never Stop Learning.
But for pasteurizing, isn’t it Baldwin’s Table 5.1 that needs to be used, which shows 3/4" as 55 mins at 145.5 F ?
He states in his notes for Table 2.2, “heating time may (counter-intuitively) be longer than pasteurization time”, but his Table 5.1 doesn’t cover times for, from frozen, so I’m not sure what you do to pasteurize, from frozen… login
See 27th post from the top, for answer by chatnoir.
Hi Oliver, - so, here we go again on this topic. I thought we had beaten it into submission long ago. Yes, Baldwin’s Table 5.1 needs to be used because we typically Pasteurize beef in order to lengthen its safe chilled or frozen storage times.
You might find it to be more a effective use of time and energy if you adjust your SV cooking event to take place closer to service and here’s why:
- Freezing previously frozen beef results in increased water loss, diminishing its quality. Better to buy fresh, cook to Pasteurize, then deep chill and freeze if you need to.
However, if you need a more precise answer than i provided earlier and are determined to Pasteurize previously frozen beef then let’s work with your example to demonstrate how to do it.
First SV cook the 3/4-inch thick beef at 145.5ᴼF for 75 minutes, according to Baldwin’s Table 2.3, to thaw and bring to temperature equilibrium. Next, continue to cook for an additional 55 minutes to Pasteurize.
Easy.
Several folks have answered your question about time and temp. Regarding the torch, I prefer using my grill (FireMagic Grill) for 1 min per side. I just prefer the taste of the grill to a torch. Good luck.
Correct on separate bagging for different doneness.
You’ve got some reading to do.
Check out the links at: http://www.douglasbaldwin.com/sous-vide.html
Especially the links for Table 2.2 and onward.
½” thick steaks are better done pan fried, than sous vide.
I’d find some other cheap steak to practice with, rather than using Wagyu.
I find it easier to clean a heavy cast iron fry pan (to sear the steaks), than setting up and dis-mantling a propane torch.