Preheat the oven to 220°C/425°F/gas 7. Blanch the potatoes for 10 minutes. Drain in a colander and shake to remove the exterior of the potato. Mix with the garlic cloves, half of the rosemary, salt and pepper to taste, 4 tablespoons of olive oil and 30g of butter in a large bowl. Arrange in a single layer in a roasting dish and roast for 45 minutes until golden.

For the parsnips, cut in half lengthwise, blanch for 10 minutes and drain. Mix with the honey, thyme, salt and pepper to taste, 10g of butter and 2 tablespoons of oil. Place the parsnips flat in a roasting dish in a layer and roast for about 40 minutes until golden.

Put the carrots in a saucepan, cover with cold water and add a pinch of salt. Boil for about 15 minutes or until cooked through. Meanwhile, finely chop the remaining rosemary and orange zest together to mix. Drain the cooked carrots and mix with the remaining butter. Season, pepper and sprinkle with orange and rosemary zest before serving.