Set sous vide machine to 60C/140F.
In a bowl, mix together soy sauce, lemon pepper, and garlic.
Put the pork tenderloin in a freezer bag with the soy sauce marinade, and remove the air through a vacuum sealer or the displacement method. Drop tenderloin in the bath for 2 hours.
Remove bag from bath. Take pork out of the bag, pat dry and lightly season with salt and pepper to taste.
Heat a large skillet on high and add oil. Sear for 60 seconds on each side. Remove from pan and place on plate to rest. Serve and enjoy!
For the best results, let pork marinate for 4 to 24 hours.