This is always going to be an easy option if you're entertaining, as all the vegetables get cooked without any attention. For four people, prepare the following vegetables: half a swede (about 5 oz/150 g) cut into 1 inch (2.5 cm) wedges; 1 small turnip, cut in half and then into ¾ inch (2 cm) slices; 2 medium red onions, peeled and cut through the root into quarters; 2 red potatoes (about 5 oz/150 g each) cut into six wedges; 4 small whole carrots and 4 small whole parsnips – scrubbed and dried well. Place them all in large bowl and add 1 fat clove of garlic, crushed; 3 tablespoons of olive oil and 1 level tablespoon of chopped mixed fresh herbs (including thyme, rosemary and sage). Toss the vegetables thoroughly using your hands.
When you're ready to cook the vegetables, spread them out on a good solid baking tray measuring about 11 x 16 inches (28 x 40 cm) and season. One thing I have found invaluable about this cooking method is being able to prepare the vegetables well ahead, which gives you that organised feeling. They can be kept covered with clingfilm or in a sealed plastic bag in the fridge for 2-3 days, ready to be roasted when required. Sprinkle with salt and a good grinding of black pepper before cooking.
Cook in a pre-heated oven, gas mark 7, 425°F (220°C), on a high shelf for 35-40 minutes, until they're tender and turning brown at the edges. When a skewer can be inserted easily into the vegetables they are cooked. Although this is a particularly lovely combination of vegetables, you can vary them according to season – celeriac, butternut squash, sweet potatoes and shallots all work equally well.