Recent research has shown that when food is cooked at high temperatures, carcinogens may be formed in very small amounts. Pre-cooking meats in a microwave oven for 2-3 minutes before broiling shortens the time on the hot pan. This could help stop the carcinogens from being made. Certain kinds of foods, like potato chips and French fries, may have higher levels of carcinogens than others. The charred residue on barbecued meats is a carcinogen, too.