Nigel Slater's Hot, Sweet Plum Chutney

Directions

Halve the plums and discard the pits. Peel and coarsely chop the onions. Put the fruit and onions into a large stainless steel or enameled pan with the raisins, sugar, chile, salt, mustard seeds, vinegars, and cinnamon stick. Bring to a boil, turn down the heat, and leave to simmer for an hour, giving the occasional stir to reduce the risk of the chutney sticking.