Traditional with lamb, this is a good way of using large windfall apples. Put the apples and water in a large pan and cook them to a pulp. Strain through a jelly bag. Boil the strained liquid for 15 minutes with half the mint, then remove the mint. Add the sugar, lemon juice and vinegar to the liquid and stir to dissolve the sugar. Bring to a fast rolling boil and boil for about 20 minutes or until setting point (110°C/222°F) is reached.
To test without a thermometer, spoon a little jelly onto a saucer, cool, then push it gently with your finger. It should wrinkle. If it does not, return to the heat and continue boiling and testing.
Stir in the rest of the mint leaves, chopped, and the green colouring. Cool the jelly until the mint is suspended. Pot and cover as for jam. Makes nine 225 g (8 oz) jars