Pre-heat the oven to 200C/400F/Gas 6.

Zest one of the lemons with a microplane and cut the rest of it into quarters. Set the zest and lemon aside.

Slice the remaining lemon into ¼-inch thick slices and arrange on the bottom of a large roasting pan or oven-safe skillet, along with the sliced yellow onion. Set aside.

In a small bowl, combine 2 tablespoons of olive oil with the lemon zest, butter, garlic powder, onion powder, and Herbes de Provence. Season with salt and black pepper, to taste, and stir with a fork to create a paste.

Using a spoon, work your way between the meat and the skin on the chicken breast so that you create a cavity for the butter. Be careful not to tear the skin.

Place the chicken on top of the onions and lemon in the pan and gently massage 1-2 tablespoons of the lemon-butter mixture under the skin.

Spread the remaining mixture all over the outside of the chicken in an even layer.

Stuff the chicken with the quartered lemon and one-third of the rosemary sprigs. Secure the legs together with kitchen string.

In a large glass bowl, toss the baby red potatoes with the remaining olive oil and fresh rosemary. Season with salt and black pepper, as desired.

Nestle the seasoned potatoes around the chicken before adding the chicken broth and whole peppercorns.

Place the pan in the pre-heated oven to roast for one hour. Tip: If necessary, loosely cover the chicken with aluminum foil after 45 minutes to prevent over-browning.

After an hour, remove from oven and check for doneness by inserting an instant-read thermometer between the leg and breast, but not against the bone. See the notes section below.

Let the chicken rest for 5-10 minutes before carving. Serve immediately topped with some of the juices from the pan and the roasted rosemary potatoes on the side. Enjoy!