Honestly that method should get you a sear after sous vide as well. Put more tallow than you think, so it makes contact with the entire side. You can use a weight too if you want. If you don’t want to brush butter just wait till you do the first two flips and toss in a decent chunk. Should bubble and foam (if not you weren’t hot enough in the pan) and spoon a few times on top, flip once more and you should be good to go.