Sous Vide Cod

Fill a large pot with water. Attach an immersion circulator to the pot. Set the temperature to 130 degrees F (54 degrees C) and the timer to 35 minutes.

Season cod lightly with salt and pepper. Top each piece with 1/2 of the lemon zest, 1 teaspoon butter, and 2 lemon slices.

Divide shallot slices between 2 resealable plastic bags. Place a cod loin on top of shallot slices. Close the bags, leaving 1 small corner open.

Lower the bags into the preheated water and submerge until all the air has been expelled. Close the corners and turn on the timer.

Remove the bags when the timer goes off. Carefully transfer cod to serving plates. Drizzle 1 tablespoon cooking liquid from each bag over each loin. Garnish with extra lemon slices.