Runner Bean Chutney

1.Trim the ends of the beans and gently pull away any stringy bits on the sides. Cut diagonally into 5mm pieces.

2.Bring a large pan of water to the boil and cook the beans for about 5 minutes until softened slightly. Drain and immediately plunge into a bowl of iced water. Leave to cool for 5 minutes, then drain and set aside.

3.Return the pan to the heat and cook the onions in 350ml of the vinegar over a medium-low heat for 15 minutes until soft, stirring occasionally.

4.Add the sugar and 250ml of the remaining vinegar, then bring to the boil.

5.Combine the turmeric, mustard seeds, nigella seeds, cornflour, a good pinch of salt and the remaining 100ml vinegar. Mix well, then tip this into the onion mixture and bring to a simmer. Cook for 3 minutes to thicken, then add the beans.

6.Bring to the boil, then reduce the heat to a simmer and cook for 10 minutes, stirring often until the beans are tender but still hold their shape and the chutney has thickened slightly.

7.Remove from the heat and spoon into sterilised jars. Will keep sealed in a cool, dark place for up to three months. Once opened, they should be stored in the fridge and used within up to two weeks.