Preheat the oven to 150°C / 300°F (130°C fan) and line two baking trays with greaseproof paper or baking parchment.
To make the caramel sauce, put all the caramel ingredients into a medium saucepan on a low heat. Stir occasionally, until the butter and sugar have melted. Once melted, turn up the heat to medium, and bring to a gentle boil. Boil for 3 minutes, and then remove from the heat and leave to cool slightly in the saucepan. Make sure to stir the mixture gently whist bubbling to avoid it sticking to the pan.
Place the oats, nuts, and seeds into a large bowl, and mix. Pour on the slightly cooled caramel sauce, and stir well until all the oats are coated evenly. Spoon the mixture onto the pre-lined baking trays, and spread out so that there is an even layer of granola on each tray.
Bake the granola for 40-45 minutes, giving it a stir every 15 minutes to ensure it bakes evenly. The granola will still be a little sticky when ready, but this will fade once the granola cools. Leave to cool in the baking trays until completely cold. Stir in the chocolate chips, and then store in an airtight container or jar.
Video
Notes
The granola should keep for a month or so, if kept in an airtight container somewhere cool and dry. There is no need to refrigerate, unless you live somewhere really warm and humid. The granola can also be frozen for 3–6 months, and will need to be left out overnight to defrost before eating.