Tip all the ingredients into a large pan and cook over a low-medium heat, stirring frequently until the sugar has dissolved and the mixture is a syrupy consistency.

Reduce the heat to low and continue to cook for 1 hr 30 mins, stirring occasionally to prevent it sticking to the pan, until the mixture has thickened and holds its shape when stirred with a wooden spoon.

Spoon into two 324ml sterilised jars (see tip, below), seal and cool. Will keep for up to three months in a cool, dark place. Use within two weeks of opening.