Preheat the oven to 200C/ gas 6/fan 180C. Put the new potatoes in a small roasting tin. Break a whole garlic bulb into cloves and nestle them between the potatoes. Dot with the softened butter, season with salt and freshly ground black pepper and roast for 30-40 minutes, turning once or twice until the potatoes are golden. Sprinkle with the snipped fresh chives or tarragon and serve with the juicy garlic squeezed out of its skin.