In a baking tin, place enough olive oil to roast the potatoes, put salt, pepper and celery salt to flavour the oil. Then insert several sprigs of herbs compatible with the meat you are roasting; rosemary and mint for instance if you are cooking lamb.
Leave for an hour, then remove the herbs.
Preheat the oven to 190 degrees Cenitgrade.
Boil potatoes for 10 minutes.
Take the lid off, empty the water and allow the steam to dry potatoes for a few minutes. Put the lid back on and give it a good shake until the potatoes are furry on the outside.
Soak the potatoes in the oil in the cold pan, do not heat the oil as most chefs do. You want the oil to soak in, not to make a hard cover.
Put the potatoes in the oven, turning the temperature down to 180 degrees Centigrade.
Keep basting for an hour, and then lightly crush each potato with a fork. Leaving small openings, not baste thoroughly again, let the oils soak right into the potatoes, continue to cook according to how crisp you like it.