- In a large, nonstick pan, heat together the ghee and milk. Bring to a gentle simmer but do not boil. Turn the heat down to low.
- Once hot, add the milk powder and icing sugar. Beat with a wooden spoon until smooth. Any lumps will disappear as it cooks.
- Cook over a low heat until smooth and glossy, about 10 minutes. Stir all the time to ensure the mixture does not burn.
- Stir in the pistachio butter and continue to cook for a further minute. The burfi is done when it is glossy and reaches 118°C/235°F on a sugar thermometer. If you do not have a sugar thermometer, place a small amount of the mixture onto a very cold plate (keep one in the fridge) and if you are able to roll the mixture into a soft ball, it is ready.
- Remove from the heat and immediately stir in any food colours (if using). I used a combination of blue and green gel good colours to achieve a natural pistachio colour. A small amount of blue neutralises yellow tones from the caramelised milk powder for a more vivid pistachio hue. Food colour is optional. You do not have to add it if you don’t wish to.
- Pour the hot burfi mixture into the greased tin. Flatten the top down using the back of a spoon. Try to get the surface as even as possible. You can lightly grease the spoon with oil if it helps create a smooth surface. If you’re not using gold/silver leaf, you can press a small handful of crushed or slivered pistachios into the surface of the burfi at this stage.
- Allow to set at room temperature for 3-4 hours. Top with optional gold/silver leaf for an Indian mithai shop finish.
- Use a large, sharp knife to cut the burfi into pieces. I cut mine into 12 squares but you can cut these as small as 1cm x 1cm if you like. These tiny squares are perfect with coffee after dinner.