You will also need: 2 bricks wrapped in aluminum foil.
To flatten chicken, stand chicken upright on your cutting board. Cut down on either side of the backbone and remove it. Cut off the first two parts of the chicken wing leaving only the top section.Press the two sides open and remove the breastbone but do not cut the chicken in half. Press the chicken as flat as possible.
Place olive oil, rosemary, salt, pepper and red pepper flakes in a shallow dish and stir well.
Place chicken in dish and coat well on both sides with marinade.
Marinate 10 minutes or up to overnight in the refrigerator.
Place chicken flat, with skin side up, on a hot BBQ. Place a brick on each half of chicken to flatten.
Cook 10 minutes. Lift the bricks off carefully, turn chicken, replace bricks and cook another 10 minutes.
Repeat until chicken is cooked through- about 20-25 minutes per side, turning once or twice.
When chicken is almost done, cook a few minutes per side without the bricks. Cook chicken on high or medium high the whole cooking time, but if it begins to burn, reduce heat.