Ok, it's not really a surprise, but we used to joke to the kids how surprised the chook would be, were it still alive!
Open the cavity of the chicken and remove excess fat from around the opening.
Tuck the wings under.
Using your fingertips, separate the skin around the two breast areas from the breast flesh.
I buy 500g butter and cut off 1 end approx 5-8mm thick x 2.
Insert the two slices of butter between the skin & the breast meat on either side.
Push 1 half of the lemon into the cavity, then insert the two halves of the whole head of garlic (around 15 or so cloves) cut side facing upwards towards the breast.
Insert the final half of the lemon.
Use kitchen twine to secure the legs so the garlic & lemon don't fall out during cooking.
Drizzle a little olive oil over he surface of the chicken and massage into the skin.
Sprinkle with salt & pepper.
Place the chicken onto a greased trivet and place it into a heavy based baking tray.
Pour about 2.5cm water into the bottom of the baking tray, which will help keep the chicken moist during cooking.
Cook at 180DegC for around 1-1½ hours. Insert a metal skewer into the thigh of the chicken, if the juices run clear (no blood!) the chicken is cooked through.
Alternatively, use a thermometer to check that the chicken has achieved 82-85DegC.
Remove from pan and cover with foil. Rest for 15 minutes before carving.
I like to moosh/smash the roasted garlic and the juice of the lemon and add to the pan juices... really, really sublime.