To prepare your vegetables:
If you’re cooking these separately and not as with my perfect roast chicken
, preheat your oven to 200°C/400°F/gas 6. Peel the vegetables and halve any larger ones lengthways. Break the garlic bulb into cloves, leaving them unpeeled, and bash them slightly with the palm of your hand. Pick the rosemary leaves from the woody stalks.
To cook your vegetables:
Put the potatoes and carrots into a large pan – you may need to use two – of salted, boiling water on a high heat and bring back to the boil. Allow to boil for 5 minutes, then add the parsnips and cook for another 4 minutes. Drain in a colander and allow to steam dry. Take out the carrots and parsnips and put to one side. Fluff up the potatoes in the colander by shaking it around a little – it’s important to ‘chuff them up’ like this if you want them to have all those lovely crispy bits when they’re cooked.
Put a large roasting tray over a medium heat and either add a few generous lugs of olive oil or carefully spoon a little of the fat from the meat you’re cooking. Add the garlic and rosemary leaves. Put the vegetables into the tray with a good pinch of salt and pepper and stir them around to coat them in the flavours. Spread them out evenly into one layer – this is important, as you want them to roast, not steam as they will if you have them all on top of each other. Put them into the preheated oven for about 1 hour, or until golden, crisp and lovely. Serve immediately, with your roast dinner and your gravy.