Heat oven to 160C/140C fan/gas 3. Line two large roasting tins (or one and cook in batches) with baking parchment. Put the porridge mix and all the flakes, nuts and seeds in a bowl and mix them together.
Put the maple syrup and oil in a big heavy-bottomed saucepan and gently heat. Add the grain mixture and stir until all the dry ingredients are coated – you are not cooking the mixture, just coating it. Spread the cereal over the parchment (it shouldn’t lie in big clumps) and bake for about 20 mins.
Remove the tins from the oven, turn the temperature up to 180C/160C fan/gas 4, then return to the oven, swapping the tins over. Cook for another 10 mins, but keep an eye on things. You want a golden toasted mixture – you may even start to smell some caramelisation – but don’t take it too far.
Take the tins out of the oven and leave to cool. Break the granola up into small chunks with your hands and add the dried fruit. Will keep well in an airtight container for two weeks. You can ‘refresh’ it by putting it all in the oven again (at 160C/140C/gas 3) for 15 mins. Eat with milk or yogurt and fresh fruit.