Runner bean chutney

Method

1. Put the chopped onions and half the vinegar into a large heavy-based saucepan and bring to a simmer. Cook for 15-20 minutes until tender.
2. Meanwhile, top and tail the beans, run a vegetable peeler down each side, then cut them diagonally into 1cm slices. Drop the sliced runner beans into a large pan of well-salted boiling water and cook for 3 minutes or until just tender. Drain and refresh under cold water, then set aside.
3. In a bowl, make a paste with the cornflour, mustard powder, turmeric and 5-6 tbsp of the remaining vinegar. Stir into the pan of simmering onions with the remaining vinegar, the sugar and salt. Simmer for 2-3 minutes, stirring, until thick. Add the beans to the pan and simmer for another 10 minutes, stirring regularly, until the beans are completely tender.
4. Meanwhile, heat a frying pan over a medium-high heat, then add the mustard seeds and sesame seeds and toss until the sesame seeds are lightly golden. Tip onto a plate and set aside to cool completely.
5. Stir the toasted seeds into the simmering chutney, then spoon into warm sterilised jars (for how to sterilise, see deliciousmagazine.co.uk/articles/how-to-make-jam). Cover the surface of the chutney with waxed discs, then seal with vinegar-proof lids.