Preheat oven to 220 degrees celsius without fan or 200 degrees celsius with fan.
Pat dry chicken, then try to lift off the skin from the meat. Generously put salt and pepper all over and inside the chicken.
Melt butter in the microwave. Add to the melted butter the olive oil, juice of 1/2 lemon, minced garlic, and parsley. Rub the mixture all over the chicken, underneath the skin, and inside the cavity of the chicken.
Stuff inside the chicken the entire head of garlic, rosemary sprigs, and squeezed half-lemon.
Tie the legs, wings, and the entire chicken together to make sure that all the ingredients we put inside the chicken won't come out or steam out.
You can add diced potatoes and carrots with the chicken to make an entire meal.
Place in the oven for one hour and twenty minutes.
Take the chicken out of the oven, let rest for three minutes, then cut into several pieces. Enjoy.