1. Place all your fruit and veg scraps in a large saucepan and cover with water.

2. Bring to the boil, turn the heat down, and let it simmer for 2 hours.

3. Pass the 'stock' pressing every bit of liquid out of the scraps.

4. Weigh the liquid and add 5% sugar.

5. Reduce over medium heat until you reach a temperature of 105C on a food probe. It should be a dark, sticky caramel.

6. Take it off the heat and allow it to cool before jarring up.