To be completely honest the safest (while still being practical) cookware is heavily enameled cast iron. Le Creuset is the goat. Big downside is they are beastly heavy and must be carefully handled to preserve enameling. Low elemental iron, low elemental nickel, and safe with acidic foods. Heavy enough to sear a steak or grill indoors, slick enough to make soft white fried eggs and fluffy scambled eggs. My wife doesnt like the weight for 3x meals a day and I don't blame her. We a Le Creuset we use for acidic cooking (esp tomato meay sauce) in order to avoid mega dosing nickel from our stainless. Misen's treated carbon steel pan does well with acidity too.