Came across this on another forum, can't vouch for it as I don't grow Runners anymore though.
Runner Bean Chutney
2lb Runner Beans Sliced and cut small
1 ½lb Onions cut into small pieces
cornflower mixture
2 tablespoons cornflour
1 ¼ tablespoons Turmeric powder
1 teaspoon Dried mustard powder
mixed to liquid with some of the vinegar
little salt
1 ½ pints vinegar
2lb Demerara sugar
1. cook beans in salted water until tender , then drain of water
2. boil onions in ½ pint vinegar until tender, put into saucepan with beans, add rest of vinegar and boil for 15 minutes.
3. Then add the cornflour mixture to the beans and onion and add the sugar, boil for a further 10 minutes .
4. Leave to cool then pot into sterilised jars.