Preheat your oven to 200°C/Fan 180°C/Gas 6. Unwrap the chicken and remove the giblets (you can save them for making homemade stock, see our tip). Pop the chicken in a roasting tin and let it sit for 30 mins-1 hr, to come to room temperature.
While the chicken is warming up, halve the lemon and insert 1 half into the chicken’s cavity. Rub the chicken all over with 1 tbsp olive oil and a pinch of salt and pepper. When it’s at room temperature, slide the chicken into the oven to roast for 50 mins.
Meanwhile, roughly chop the olives. Peel and thinly slice the garlic. Chop the tomatoes into wedges. Peel and thinly slice the red onion. Fill and boil your kettle.
After 50 mins, add the olives, garlic, tomatoes and onions to the roasting tin, around the chicken. Add 1 tsp dried oregano and 250ml boiling water. Roast the chicken for another 30 mins, or till it’s cooked through. Check by piercing the fattest part of a leg with a knife – the juices should run clear. If not, roast for another 5-10 mins and check again.
When it’s done, lift the chicken out onto a warm plate or a board, loosely cover with foil and rest for 30 mins before carving. Serve the chicken with the roast veg, drizzled with the pan juices and garnished with chopped parsley leaves and wedges of lemon.