Heat oven to 190C/fan 170C/gas 5. Have a shelf ready in the middle of the oven without any shelves above it.

Scatter 1 roughly chopped onion and 2 roughly chopped carrots over the base of a roasting tin that fits the whole 1 1/2 kg chicken, but doesn’t swamp it.

Season the cavity of the chicken liberally with salt and pepper, then stuff with 2 lemon halves and a small bunch of thyme, if using.

Sit the chicken on the vegetables, smother the breast and legs all over with 25g softened butter, then season the outside with salt and pepper.

Place in the oven and leave, undisturbed, for 1 hr 20 mins – this will give you a perfectly roasted chicken. To check, pierce the thigh with a skewer and the juices should run clear.

Carefully remove the tin from the oven and, using a pair of tongs, lift the chicken to a dish or board to rest for 15-20 mins. As you lift the dish, let any juices from the chicken pour out of the cavity into the roasting tin.

While the chicken is resting, make the gravy. Place the roasting tin over a low flame, then stir in 1 tbsp flour and sizzle until you have a light brown, sandy paste.

Gradually pour in 250ml chicken stock, stirring all the time, until you have a thickened sauce.

Simmer for 2 mins, using a wooden spoon to stir, scraping any sticky bits from the tin.

Strain the gravy into a small saucepan, then simmer and season to taste. When you carve the bird, add any extra juices to the gravy.