Is there a permissible way to turn off a cooking flame on yom tov? I don’t want to leave a flame burning overnight if it can be avoided.
ב"ה Shalom The best solution would be to install what is called חגז "Chagaz" which is a timer to which the gas is attached to and like a Shabbat clock which turns off the lights by a timer, this device closes the gas. It is available in Israel by Machon Tzomet. http://www.zomet.org.il/eng/ However, if this is not available, and you are concerned about leaving on the gas all night for safety reasons, you may extinguish the flame in an indirect manner in the following way. You should fill a small pot with water that you intend to use for drinking something hot or the like and wait to the water boils over and extinguishes the flame. Once that is done, you may shut the gas knob closed. When you need the flame again you can transfer a candle from an already existing flame and rekindle the gas. There are, however, Rabbis who have their reservations about this method when done regularly. But, in a case of concern about safety, there are many prominent Rabbis to be relied upon to extinguish the flame as described. (See שו"ת באר משה ח"ח, סי' קנ"ז, קע"ו, שו"ת דבר יהושע ח"ב סי' פ"ד, חזון עובדיה הלכות יום טוב עמ' נח-נט, שו"ת יחווה דעת ח"ב סי' ס"ו, ספר כי בא מועד הלכות יום טוב סי' תקי"ד, עמ' פח. ) All the Best. שנה טובה וגמר חתימה טובה