- Place courgettes in a large strainer and sprinkle with the salt.
- Stand for two hours, rinse under cold water and pat dry with paper towels.
- Combine courgettes in a large saucepan with apples, onions, chillies, sugar and spices, stirring until the sugar is dissolved.
- Bring to the boil. Simmer, uncovered, for about 20 minutes, stirring occasionally, until thick.
- Pour into hot sterilised jars and seal when cold. Makes about 8 cups.