ElsieD got it right, and I do what she does. 133-134°F for 24hr works for most beef (short ribs take longer) if you want medium rare. I do tri-tip that way after running a Jaccard over it a few times. Comes out fork tender and medium all the way through.
I pre-season with a chef salt containing a 3:5:2:1 combination of (salt: black pepper: powdered garlic: smoked paprika).
Torch it once at the end after it has cooled somewhat so that you don't overheat and destroy that nice pink flesh.
Thin sliced it should melt in your mouth.