If your salmon is already frozen and vacuum sealed, don’t season before cooking. If your salmon isn’t sealed, sprinkle all over with salt and pepper, and place in sous vide bags.
Set sous vide to 130 F and turn it on for 70 minutes (note: I tend to set it for 125 for 60 minutes and finish it in the oven or on the stovetop).
When the timer goes off, remove salmon from the bags, pat dry, and if you haven’t already, season with salt and pepper generously.
Heat the olive oil in a large skillet over medium-high heat. Once very hot, add the salmon (it’s now completely cooked, you just want to sear it for some texture) and sear on each side for 1 minute until golden brown.
Remove from the pan, squeeze some lemon juice on top of each fillet and enjoy plain or with whatever sauces/toppings you like.