2 tbsp sunflower oil
For the toffee
40g brown sugar
2 tbsp golden syrup
1 pinch Salt
Heat the oil in a large saucepan, sprinkle in the popcorn and swirl the pan to coat it evenly in oil. Cover with a tight-fitting lid; turn the heat down to low, and listen for popping noises. As soon as the popping quietens down, take it off the heat.
Meanwhile, melt the butter, add the brown sugar and golden syrup and stir over a high heat for 1-2 minutes.
Tip half of the popcorn out of the saucepan and toss with 25g butter and a pinch of salt.
Pour the toffee over the remaining popcorn, replace the lid on the pan and shake to mix the toffee sauce. Pour out into bowls, cool a little and serve.