Preheat the oven to 425°F (220°C). Line a large baking sheet with foil and place a wire rack on top.
Place the chicken breast-side down on a cutting board. Using kitchen shears or a sharp knife, cut along both sides of the backbone to remove it.
Flip the chicken over and press firmly on the breastbone to flatten the bird into a spatchcock shape.
In a small bowl, combine the olive oil, salt, black pepper, minced thyme, minced garlic, lemon zest, and lemon juice.
Rub the mixture all over the chicken, working some under the skin where possible and covering the exterior evenly.
Place the chicken breast-side up on the prepared rack and roast in the preheated oven for about 45 minutes, or until an instant-read thermometer inserted into the thickest part of the thigh reads 165°F (74°C) and the skin is golden and crispy.
Remove the chicken from the oven and let it rest for 10 minutes before carving and serving.
