How to Make It
Working with one piece at a time, place the chicken between 2 pieces of plastic wrap and pound with a mallet, a rolling pin, or the bottom of a skillet to an even ½-inch thickness.
Heat a large skillet over high heat. Season the chicken with ¾ teaspoon salt and ¼ teaspoon pepper. Add 2 tablespoons of the oil to the skillet and heat for 10 seconds. Cook the chicken, in batches (adding an additional tablespoon of oil if necessary), until golden brown on one side, 2 to 3 minutes. (Reduce heat if the skillet starts to become very dark.) Turn the chicken and cook until cooked through, 30 seconds. Transfer to a plate; reserve the skillet.
Reduce heat to medium-high. Add the broth, thyme, and lemon to the reserved skillet. Cook until the lemon is tender and the broth is reduced by half, 3 to 4 minutes.
Remove the skillet from heat. Add the butter and stir to combine. Serve the chicken topped with the sauce and lemon slices.