Preheat oven to Gas Mark 6, 200˚C, fan180˚C. Heat oil and sweat onion and garlic until softened. Decant to a bowl and cool.
Whizz the bread in a food processor with parsley. Add to onion and garlic mix, along with zest, and season. Spoon the stuffing into the chicken neck cavity.
Place in a roasting tray, smother over butter, season, add ½ cup of water and roast for 1hour 20 minutes. To test, insert a skewer into thickest part of thigh. It is cooked through when juices run clear; if not, cook 10 minutes more.
Scatter chicken with some chopped parsley, leave to rest for 10 minutes, then carve. Bubble down juices in pan and serve along with new potatoes and vegetables.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.