This goes well with curries or served alongside cheese. The recipe will make about two 450g jars, which will store for a year or so in a cool, dark place. If your marrow is smaller (or bigger), cut down (or ramp up) the other ingredients in proportion.
900g marrow, peeled, deseeded and chopped
225g red onions, peeled and finely chopped
450g tomatoes, roughly chopped
300g demerara sugar
100g sultanas
300ml wine or cider vinegar
thumb-sized piece of fresh ginger, finely chopped
1tbsp pickling spice or 2tsp each black peppercorns and whole allspice, tied in a piece of muslin or put in an enclosed tea strainer
Method
Place all the ingredients in a large stainless steel pan and bring to the boil. Reduce the heat and simmer for 1½ hours, stirring occasionally, until the mixture is thick and jam-like.
Allow to cool a little, take out the spices and spoon the chutney into sterilised jars.