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

Heat water to temperature based on your preferred doneness for your burgers. (126 degrees F = rare, 133 degrees F = medium-rare, 140 degrees F = medium, 147 degrees F = medium-well, 158 degrees F = well done). (We like 158 for our burgers.)

Divide ground beef into 4 even portions and form into round patties. Season both sides to taste.

While water is heating, season hamburger patties and place them in a single layer in a 1-gallon plastic zip-top bag or vacuum seal bag (and seal the bag). Can put hamburger patties into more than one bag if needed.

When water is heated, lower each bag into the water making sure the meat is fully submerged. Fold top of bag over the side of the stockpot. Clip bag to the side, if needed.

Set timer for cook time. Cook time depends on thickness of your steak (1/2-inch = 15 minutes, 3/4-inch = 22 minutes, 1-inch = 30 minutes). 

After cook time is finished, remove bags from sous vide and remove hamburger patties from the bag. Preheat heavy skillet over high heat. Place 1 Tbsp butter or olive oil in skillet then sear hamburger patties 1 minute on each side.