Heat an oven to 200°C fan (220° no fan).
Remove the butter from the fridge and let it soften. Finely chop the chives and garlic and mix in with the butter to make the garlic butter Leave it out the fridge to remain soft.
Roughly chop your onion, carroy and celery and smash the remaining garlic cloves. Scatter them over the botton of a baking tray alongside the thyme and rosemary.
Place the chicken on top of the vegetable base.
Slice the lemon in half and stuff it into the cavity with the remaining thyme and rosemary.
Gently separate the skin from the breast from the cavity side. Stuff the garlic butter under the skin and use your fingers to massage it all the way along the breast until it is distributed evenly.
Cover the skin in olive oil and season with salt and pepper.
Put the chicken into the oven for 1 hour to 1 hour and 15 minutes. The chicken should be 72°C at the thickest part of the breat, and the juices should run clear.
Remove the chicken from the tray and cover with tinfoil. Leave it for 15 minutes to rest.
Put the roasting tray on the hob over medium heat. Add the flour in and mix in with the vegetables.
Pour in the chicken stock bit by bit and mix it in, letting the flour mix in without clumping.
Cook over medium heat until the flavour has all released from the tray and the gravy as thickened. Strain into a jug to serve!
