Using a sharp knife or pair of poultry shears, remove and discard the backbone from the chicken.
Lay the chicken on a flat surface, skin side up, and flatten the breast by pressing with the heel of your hand-the chicken should be as flat as possible.
Rub with lemon juice and season generously with salt and pepper.
Heat the oil in a large, heavy skillet over medium-high heat until it is hot but not smoking.
Place the chicken in the oil skin side down and place a lid or other skillet on top of the chicken.
Place two bricks or other weights totaling about 10 pounds (4.5 Kg) on top of the lid and cook the chicken over medium-high heat until the skin is golden brown, about 12 minutes.
Remove the weights and lid and turn the chicken over.
Replace the lid and weights and cook 12 minutes more.
To test if fully cooked, pierce the thigh with the tip of a sharp knife-the juices should run clear.
Transfer the chicken to a serving platter and cover with aluminum foil.
Let rest for 10 to 30 minutes before cutting into serving pieces.