You will need a bowl that is heat-safe and will be able to sit on top of a saucepan safely.
In the saucepan, you’ll place about an inch or so of water – enough to simmer, but not enough to reach the bowl itself. You will also need a 9×9 inch dish (or comparable size) that has been greased with butter. Line it with some parchment paper, leaving the edges hanging over to easily lift the fudge out of the pan.
Combine all of the ingredients except the salt in the bowl. Turn the eye on medium heat and let the water begin to simmer.
Stir the ingredients together, and continue to stir, until the gentle heat melts it all and it is combined and smooth. This will take around 5-7 minutes, depending on your water temperature.
Spread the fudge into your prepared pan. Sprinkle the salt over the top.
Chill the fudge in your fridge for about 2 hours until nice and firm.
Run a knife around the edges of the pan and then lift the fudge out. Cut it into small squares, about 1 1/2 inch square, with a sharp knife.