In a small bowl, combine all the marinade ingredients. Stir to combine. Place beef tenderloin in a zip-top plastic baggie then pour in the marinade. Seal the bag and refrigerate for at least 30 minutes or overnight.

Fill a stockpot or sous vide container 3/4 full of water. Place on heat-proof surface and add immersion circulator.

Heat water to temperature based on your preferred doneness for your beef. We prefer our beef cooked to 140 degrees F for medium. You can go up to 149 for well-done beef or 133 for medium-rare beef.

Remove the beef tenderloin from the marinade. Discard marinade. Place the beef in a vacuum seal bag. Add 2 tablespoons of butter. Remove air and seal bag.

When water is heated, lower the bag of beef into the water making sure the meat is fully submerged.

Set timer for cook time. Cook time depends on the thickness of your meat (2-inch = 2 hours, 2 1/2-inches = 2 hours, 30 minutes - 3-inch = 3 hours).

After cook time is finished, remove bags from sous vide and remove beef from the bag.

Preheat heavy skillet over high heat. Place 1 Tbsp butter or olive oil in skillet then sear beef tenderloin for 1 -2 minutes on each side.