Fill up a large pot with water and add your immersion circulator to the side. Set the temperature to 155F and let the water come to temperature.

While the water is heating, prepare the chicken. Trim off any excess fat from the top of chicken and remove the giblets from inside. Reserve those for later use in chicken stock, if desired. Rinse your chicken in cold water if desired (but not necessary) and pat dry with a paper towel.

Stuff the cavity with lemons, onions, and garlic if desired. Make sure the cavity is completely full so that as little air stays inside as possible. Tie the legs with kitchen twine to hold everything.

Place the chicken into a sous vide bag large enough to hold it so it can be sealed properly. You can also use a large vacuum sealer bag.

Seal your bag using the water displacement method (instructions in video). Submerge the chicken into the temperature controlled water bath. Use a weight such as a heavy kitchen utensil to make sure it is fully submerged. Add a layer of foil to the top of the pot to keep the heat in. Cook it for 1 hour and 45 minutes to 2 hours.

Remove the chicken from the water and allow to rest for 10 minutes before slicing it open to check doneness. The liquid may still be pink inside but it will be fully cooked through if the internal temperature is at least 155F.

Add the chicken to a baking dish and pat dry with paper towels. Season with dry seasonings. Place under the broiler until the skin crispy and golden brown. You may have to rotate the pan to get an even crisp.

Let cool for 5 minutes before slicing and serving with your favorite side dishes.