Firstly, my view is that roasting potatos with SKIN ON is best. All the flavour lies in the skin.
Secondly, frying in olive oil is fine. see here:
No...
This rumour may have been started back in 2001 when contaminants were found in Spanish refined olive oil.
Polycyclic aromatic hydrocarbons are a group of chemicals which are formed when petroleum, petroleum products, coal, wood, cellulose, corn, or oil are burned. There are over 100 PAHs which have been studied. During oxidation and detoxification in the liver they are thought to form substances which damage DNA, starting a chain of events which could lead to cancer. A few of them have been classified by the EPA and The Department of Health and Human Services as carcinogenic to animals in studies and probably carcinogenic to humans.
A person's exposure at home to PAHs would likely be through tobacco smoke, wood smoke, vehicle exhausts, asphalt roads, coal, coal tar, wildfires, agricultural burning, waste incineration, creosote-treated wood products, cereals, grains, flour, bread, vegetables, fruits, meat, processed or pickled foods.
At work you could be exposed to PAHs in coal tar production plants, coking plants, bitumen and asphalt production plants, coal-gasification sites, smoke houses, aluminum production plants, coal tarring facilities, municipal trash incinerators and by inhaling engine exhaust. PAHs can also be found in the mining, oil refining, metalworking, chemical production, transportation, and the electrical industry.
Twenty years ago there was a food scare when PAHs were first being researched. They were found in meat and other foods which had been cooked at high temperatures, such as grilling and charring. The American Institute for Cancer Research recommends to avoid charring meat when grilling, pre-marinade, which somehow minimizes PAH formation, and minimize the amount of grilled meats consumed. (Grilled vegetables or fruit do not form PAHs).
Many foods naturally contain small quantities of PAHs. Olive oil, like other vegetable cooking oils, has been found to contain minute amounts of up to 17 PAHs such as benzanthracene and chrysene. Unripe olives tended to have more than ripe olives.
Burning any cooking oil can increase the amounts of PAHs. Oil of any kind which has been repeatedly heated to its smoking point will lose it's natural antioxidants and begin to accumulate free radicals and other cancer causing substances. Whether this has actually caused cancer in humans has never been proven. Commercial industrial kitchens which fry foods would be where this sort of thing might happen. It is unlikely that you would repeatedly fry at continuous high temperatures with the same oil at home. In commercial operations the oil is examined regularly with a rancidity test and discarded before it gets to a dangerous stage. Olive oil is typically not used in commercial kitchens as it is much too expensive. Cheaper oils like canola, corn or peanut oil are used instead. Extra virgin olive oil has fewer free fatty acids and more antioxidants which soak up free radicals. So heating it would produce fewer free radicals than a lower grade olive oil.
It is unlikely that in home use olive oil or other cooking oils would be a significant source of PAHs.
Sometimes when people hear cancer, they panic and forget that we are surrounded by possible carcinogens, ranging from nearly every food we eat to sunlight. Although a substance we are exposed to is capable of causing cancer, the probability that this actually happens may be vanishingly small. Exposure to second hand cigarette smoke or going outside without sun block is probably thousands of times more likely to cause cancer than burning your cooking oil. Sources: http://www.oliveoilsource.com/oliveoildr-cancer.htm
My recipe is:
Give them a good scrub, leave skin on, slice about 15mm thick, toss in a bag with olive oil to coat and then lay them out in a baking tray cover with herbs of choice say rosemary, thyme and coarse sea salt. Bake at 250deg C for 20 minutes each side. I prefer Dutch Cream spuds...
