Begin by preheating your oven to 425°F (220°C).
In a mixing bowl, combine the minced garlic, chopped thyme, lemon zest, olive oil, salt, and pepper. Stir well until a paste forms.
Take your chicken and gently separate the skin from the breast. Apply half of the previously prepared paste underneath the skin, ensuring it's evenly distributed.
Rub the remaining paste over the entire surface of the chicken.
Stuff the chicken cavity with thyme sprigs and lemon slices.
In a roasting pan, place the thinly sliced onions creating a bed for the chicken. Position the chicken on top.
Dot the chicken's surface with butter.
Pour the chicken stock around the chicken in the roasting pan. This will provide moisture, ensuring your Lemon Thyme Roast Chicken doesn't dry out and infuse added flavor.
Roast in the preheated oven for about 1 hour and 20 minutes. Baste occasionally with the pan juices. Ensure the chicken's internal temperature reads 165°F (74°C) and the juices run clear.
Once done, remove the chicken from the oven and let it rest for 10 minutes before serving. This ensures the juices redistribute, offering a moist and flavorful bite.