Burger:

1. Set up a water bath of  8 quarts of water. Turn the immersion circulator on to 132°F (55.6°C). Make sure there is enough room for the water to flow around the bath.
2. Weigh your portion of ground beef and shape into a patty.
3. Sprinkle a generous amount of salt and pepper onto both sides of each beef patty.
4. Put each patty into a separate plastic zipper-lock bag.
5. Push all the air out of the bag by sealing it almost all the way, then slowly lower the bag into a pot of hot water that has been preheated to the right temperature.
6. Finish closing the bag completely just before it fully sinks into the water.
7. Leave in the water for at least 45 minutes and at most 2 hours.
8. Remove the patty and rest for at least 10 minutes.
9. Preheat the cast iron pan to a medium high heat.
10. Place the patties on the grill or skillet and cook for 3-4 minutes per side or until they reach your desired level of doneness. During the last minute of cooking, add a slice of cheese to each patty and let it melt.

Burger Sauce:

1. In a small bowl combine all ingredients. Use a whisk to mix thoroughly.

Assembly:

1. Toast buns.
2. Spread the sauce on the bottom half of each bun.
3. Add a patty with melted cheese on top.
4. Finish with the top half of the bun.