Preheat the oven to 200°C/400°F/gas 6. Peel the potatoes and cut them into three or four pieces, then rinse them. Place the potatoes in a large pan, cover with water and add 1 teaspoon of Maldon salt. Bring to the boil and simmer for 10 minutes or until the potatoes are almost cooked.
Drain the potatoes in a colander, and leave them in it; give them a good shake. The potatoes need to be shaken up to give them a rough exterior without breaking them up, as this will give them a crispy outside when cooked.
Melt the goose fat in a pan. Place the potatoes in a heavy roasting pan and cover them with the fat. Add the springs of herbs and the optional garlic and roast for 40 minutes or until golden brown. Serve hot – with plenty of Maldon salt.