Once the stick of butter has reached room temperature and is softened, add butter, gochujang paste, garlic, sesame oil, lemon juice, honey and salt to a food processor or blender. Process the ingredients until combined and smooth. 

Place butter lengthwise in the center of parchment paper, then roll the butter to make a circular log. Wrap in plastic wrap and refrigerate. 

Set sous vide machine to 55C/131F.

Salt and pepper the rib eye to taste. Put the steak in a freezer bag with crushed garlic, and remove the air through a vacuum sealer or the displacement method. Drop steak in the bath for 1 hour.

Remove bag from bath. Take steak out of the bag, pat dry and season with salt and pepper to taste. Heat pan on high and add oil. Sear for 60-90 seconds on each side. Remove from pan, put a glob of gochujang butter on the top and let rest for 5 minutes

Add lemon half to the hot pan, cut-side down. Cook until blackened, and remove from pan.

Slice and serve steak with gochujang butter, spritzing a little lemon juice on every piece.