Method:

1. Heat butter and sunflower oil to frying pan and add sliced onions
2. Once the onions start to soften add the sugar, pinch of salt and pepper
3. Keep turning the onions every 30 seconds to get an even colour – they should become a dark golden colour
4. Once cooked put to one side
5. Heat a griddled skillet and slightly oil the franks before adding to the pan
6. Cook for about a minute and a half on each side
7. Cut open buns, then add the franks followed by a generous helping of onions
8. Top of with a splodge of tomato chutney

Tom's top tip: Cooking with both oil and butter will help prevent the butter from burning