Fill a large pot with water and set your sous vide temperature to 175 degrees.
While the water is heating up, remove corned beef from the package, drain excess liquid and rub spice packet on both sides. If you’d like to rinse off the corned beef to make it less salty, this is when you would do that.
Add spiced corned beef to a freezer ziploc bag and remove as much air as possible.
Once the water bath is heated to 175, submerge the bag in the water bath keeping one inch of the bag open. The pressure from the water will remove the rest of the air from the ziploc as it goes in. Once all the air is out, seal the bag completely.
Make sure the corned beef is fully under the water and use a clip to keep the bag from floating around while cooking. Add some foil to the top of your pot to keep the water from evaporating too quickly so it can stay at the correct temperature.
Set the timeer and cook for 10 hours. Once it’s finished, remove from the bag and pat dry with a paper towel. You can store it in the fridge at this point or slice and serve while it’s warm.
OPTIONAL: heat up 1 tbsp avocado oil in a cast iron skillet over high heat. Once avocado oil begins to smoke, sear corned beef for 1-3 minutes each side to get a browned crust on the outside.