Preheat oven to 400ºF and line a large rimmed baking sheet with a piece of parchment paper or a Silpat™ baking sheet. Set aside.

Make thin slices of both lemons, then cut the slices from one lemon into quarters. Break two of the rosemary sprigs into small pieces. Set aside.

Arrange the chicken on the prepared baking sheet without overcrowding. Use a sharp knife to gently lift the skin and sprinkle the meat with salt and black pepper, as desired.

On the thickest part of the chicken, create a pocket under the skin with the knife and insert the quartered lemon slices, minced garlic, and the small pieces of rosemary inside.

Scatter the whole lemon slices and rosemary sprigs onto the baking sheet and place into the pre-heated oven.

Remove from the oven and brush the pan juices over the chicken with a clean pastry brush. Cover loosely with foil and rest for 5 minutes. Remove cover and brush pan juices over the chicken again.