In a large saucepan, combine the apples, onions, sugar, raisins, ginger, mustard seeds, and salt.
Pour in the cider vinegar, ensuring all ingredients are mixed well.
Bring the mixture to a boil over medium heat until the sugar dissolves.
Reduce the heat to a simmer and let it cook uncovered for about 1 to 2 hours, stirring occasionally.
Once thickened, transfer the hot chutney into sterilized jars and seal immediately.