Season 4 boneless skinless chicken breasts with ½ teaspoon salt and ¼ teaspoon ground black pepper.
Add ¼ cup of the ⅔ cup refrigerated basil pesto to the bottom of a greased 9 x 13-inch baking dish. Lay the chicken breasts on top of the pesto, then top them evenly with the remaining pesto.
Lay 6 ounces sliced fresh mozzarella evenly over the tops of the breasts. If using, add 1 cup cherry tomatoes to the baking dish around the chicken.
Bake for 25-30 minutes, until the thickest part of the chicken reaches 165 degrees Fahrenheit on a thermometer. Serve immediately.
Notes
Leftover and Make-Ahead Instructions
Fridge: Store leftovers in an airtight container for up to 5 days. Reheat in the microwave or at 350°F until warmed to 165°F.
Freezer: Freeze without the mozzarella. Thaw completely, add the cheese, and bake as directed.
Make Ahead: Assemble up to 2 days ahead, cover, and refrigerate. Let it sit at room temperature for 30 minutes before baking.