Stovetop Version: Follow the recipe above up to the point of grilling. Heat an extra-large lightly greased skillet over medium-high heat. Pan sear the top side of chicken, partially covering, until beautifully golden, about 5 minutes, lowering the heat to medium if getting too dark. Once golden, turn over, and continue cooking over medium heat, for another 5-6 minutes, again lowering the heat to med-low, if getting too dark. Once the chicken is cooked through (160F at the thickest part) top with the mozzarella slices, cover the pan, and cook on medium-low heat until the cheese is melty, about 2-3 minutes. Continue with recipe, making the tomato relish while the chicken is cooking.
Feel free to marinate the chicken ahead and make the salad ahead.
Sometimes I’ll tuck the pesto, under the melting cheese, or over the cheese, under the tomatoes- up to you.