Place in a ziplock freezer bag and use the water displacement method to remove the air from the bag.
Cook for 1 ½ hours. Remove burgers from the bag and pat them dry. Let sit for 5-10 minutes.
Heat a cast iron skillet over medium high heat while the burgers rest.
Add the avocado oil, then the burgers. Sear for 60-90 seconds per side, until a crust is formed.
Remove and serve on buns with condiments.
**Water displacement method is recommended to avoid smashing the burgers.
When using the water displacement method, use the instructions above to remove the air from the sealable bag to avoid bacteria entering the bag.
The burgers should be fully submerged in the water bath. If air gets in the bag while the burgers are cooking and the bag starts to float, just open the ziplock bag, remove the air and reseal it again.