Season the chicken breasts all over with salt and pepper. Let rest while the oven preheats to 375°F.
Lay the lemon slices and rosemary pieces all over the bottom of a roasting pan. Carefully pour the chicken broth into the baking dish.
A little bit of chicken broth in the baking dish is essential to easily making chicken breasts moist and tender, and I've been successfully using this technique for years. It never fails. If the pan is dry and the air in the oven is dry, the rate of removal of moisture from the meat surface gets very high, which dries out the meat pretty quickly. A little bit of liquid in the baking dish creates humid environment in the oven, which slows down the rate at which moisture is removed from the surface of the meat. This results in very moist, succulent chicken breast meat.
Place the chicken on top, leaving space in between the breasts so they have room to crisp up. Drizzle with the olive oil.
Baked until the breasts are golden and cooked through, and reached the internal temperature of 160F. Depending on your oven and the size of the breasts, this will take about 30-45 minutes.
If you want the tops to be more browned, turn on the broiler for a few minutes towards the end of baking. Keep a close eye on the chicken breasts as they will brown quite quickly.
Remove the breasts from the oven and transfer to a serving dish. Let rest for 5 minutes then serve with the pan juices spooned all over the flesh.