Pound each chicken breast between a fold of plastic wrap or parchment paper to a uniform thickness, approximately ¾ inch.

To big stockpot full of water, add salt, bay leaf, squeeze in both lemon halves, and add the rind as well. Set a steamer basket in the stockpot and place the pounded chicken breasts in a single layer on the steamer. Let sit at room temperature for 30 minutes.

Bring stockpot just barely to a boil (minimum temperature 175°F, higher is OK), cover the pot, turn off the heat, and let stand for 20 minutes, which will delicately cook the chicken. The internal temperature of the chicken should reach at least 160–165°F. Transfer chicken to a plate, let cool, then refrigerate until ready to use.