500ml / 1 pint milk 225g / 8 oz butter, chopped into pieces 1.8kg / 4 lbs super fine/caster sugar 450g / 1 lb of condensed milk Butter a 30cm x 10cm /12" x 4" or 18cm/ 7" square tin. In a large, deep pan saucepan, absolute 4 pint minimum but preferably larger (a stock pot works very well) heat the milk to a low simmer then add the butter. Stir until melted. Add the sugar and stir until all the sugar has dissolved. Raise the heat to high and bring the sugar to a hard boil for 5 minutes (the mixture should boil really fiercely which helps to reduce the liquid and colour the mixture) stirring all the time to prevent the sugar from sticking and burning. If you have a thermometer take the temperature to 120°C/ 250°F (also known as hard ball stage in candy and toffee making). Once the sugar is boiling, slowly add the condensed milk- TAKE CARE - the sugar is at a very high temperature and may splatter. Stir well then lower the heat and simmer for 20 mins. The mixture will bubble and resemble a moon crater, but don't be put off, keep cooking. The mixture will also start to slightly darken. After twenty minutes or once the mixture is visibly thickened, remove the pan from the stove and beat the mixture vigorously for 5 - 10 mins (you could use an electric mixer here as it will save your arm from aching, add any optional flavourings (see note below). Pour into the greased pan and when the tablet is cool but still soft, cut into 2.5cm (1") squares - you can even put the pan in the freezer to make sure it is completely cold. Wrap in greaseproof paper and store in an airtight tin.