The best roast potatoesjo

It does not matter how good your meat or gravy are, if you get the roast potatoes wrong - it's all over. You can make these in advance if you want to and reheat them later, or even just get them up to the stage where they're coated in the fat, then cook them another day.

Preheat your oven to 220 # 730-C / 425 # 730-F / gas 6. Add the potatoes, carrots and parsnips to a large pan of salted boiling water. Cook on a high heat for 8 to 10 minutes, or until the outside of the parsnips and potatoes start to break down slightly. Drain in a colander and leave to steam dry for a couple of minutes, then toss the colander a few times to fluff up the potatoes - this will make them super crispy later on.

Put a large roasting tray on a high heat. Add a couple of lugs of olive oil, the butter or fat - use the fat from your Christmas bird, if you can - and allow it to heat up. Add the rosemary leaves. Break the garlic into unpeeled cloves and add to the tray.

Carefully tip your drained veggies into the tray. Use a fish slice to delicately coat everything in the flavours. Add the lemon and clementine zest with a good pinch of salt and pepper and mix again. Cook in the hot oven for around 45 to 50 minutes, but check them after 35 and jiggle the tray for even cooking. When they're golden and crispy they're perfect and ready to serve.