METHOD

1. Place the salt, sugar, garlic, fennel, juniper, peppercorns, half the lemon slices, half the tarragon, the bay leaves and 1 litre of the water in a medium saucepan over high heat and bring to the boil. Cook for 10 minutes, stirring to dissolve the salt. Allow to cool slightly and pour the brining liquid into a large (10-litre-capacity) non-reactive container+. Add the remaining 7 litres of water and stir to combine. 
   
2. Using your hands, carefully loosen the skin from the flesh of the turkey breasts. Tie the legs with kitchen string and tuck the wings underneath. Lower the turkey, breast-side down, into the brine. Cover and refrigerate for 6 hours (but no longer). 
   
3. To make the lemon garlic butter, place the butter, lemon rind and garlic in a small bowl and mix to combine. 
   
4. Preheat oven to 180°C (350°F). Lightly grease a large wire rack over a roasting pan. Remove the turkey from the container, discarding the brine, and pat dry with absorbent kitchen paper. Using your hands, spread the butter under the skin. Place the remaining lemon and tarragon inside the cavity. Place the turkey on the rack and brush with the oil. Pour the extra water into the pan, cover with lightly greased aluminium foil and roast for 1 hour. Uncover and roast for a further 45 minutes or until golden and the juices run clear when tested with a skewer. Cover with aluminium foil and allow to rest for 20 minutes, before serving. Serves 6–8
   

+ Non-reactive materials include glass, plastic and stainless steel.