Step 1

To butterfly the chicken, place chicken breast-side down on a chopping board. Use kitchen scissors to cut down either side of the backbone to remove. Discard (or freeze to use in stock). Turn the chicken breast-side up, then use your hand to push the bird flat, breaking the breast bone.

Step 2

For the brine, place 1L (4 cups) water in a large saucepan over high heat. Bring to the boil, then add salt and sugar, stirring until dissolved. Remove from heat, then add 2L (8 cups) iced water and allow to cool.

Step 3

Add remaining ingredients and chicken. Cover and refrigerate in brine overnight. The next day, remove chicken from brine, discarding brine, and pat dry with paper towel.

Step 4

Transfer the chicken to a plate and return to the fridge uncovered for at least 1 hour or until ready to cook (the dry air in the fridge removes moisture from the skin, making it extra golden and crisp when cooked).

Step 5

Remove from the fridge 1 hour before cooking to allow chicken to come to room temperature.

Step 6

Preheat a barbecue with a lid to medium-high heat (alternatively place a chargrill pan over medium-high heat and preheat oven to 220°C).

Step 7

Brush chicken and lemons with oil. Cook chicken, skin-side down, for 2 minutes, then add lemons, cut-side down, and cook for 2-3 minutes until chicken is golden and slightly charred.

Step 8

Reduce heat to medium-low. Turn chicken and lemons. Close the barbecue lid and cook for 35-40 minutes until juices of chicken run clear when thickest part of thigh is pierced and lemons are soft.

Step 9

(Alternatively, transfer chicken and lemons to a roasting pan and cook for 35-40 minutes until cooked through.)

Step 10

Remove from oven and rest, loosely covered with foil, for 10 minutes.

Step 11

Meanwhile, for tahini sauce, bring a large pan of water to the boil over medium-high heat. Blanch the herbs and spinach for 20 seconds or until tender, then refresh in iced water and drain, squeezing out excess liquid.

Step 12

Place in a small food processor or blender with remaining ingredients and 2 tbs water. Season and whiz to combine.

Step 13

Cut chicken into pieces and place on a platter or tray with lemon and tahini sauce. Scatter with parsley and oregano to serve.