Gather all ingredients. Preheat the oven to 400 degrees F (200 degrees C).
Cut chicken breasts in half horizontally and, if needed, pound each to even thickness with a meat mallet. Season both sides with salt.
Heat oil in a 12-inch oven-proof skillet over medium heat. Add chicken to skillet and cook until lightly browned, 3 to 4 minutes. Flip and cook the other side until lightly browned, 3 to 4 minutes. Remove skillet from heat.
Spread 1 tablespoon of pesto on top of each chicken portion.
Place 1 tomato slice on top of each chicken portion and top with 2 slices of mozzarella.
Transfer skillet to the preheated oven and bake until cheese is melted and chicken is cooked through (165 degrees F or 74 degrees C), about 10 minutes.
Serve topped with torn basil leaves. Recipe developed by Barrett Heald