Green food color (optional)
Soak pistachios in warm water for 30 mins.
Drain all water, peel the pistachio, and blend it in a mixture for a fine paste.
Take a broad non-stick pan and cook sugar and 1/2 cup water on medium flame till the syrup is string consistency, stir continuously to avoid burning.
Add Pista paste to it and continuously mix for 5-7 mins on low flame till the mixture leaves on the sides of the pan. Add 2-3 drops of green edible food color as per your liking.
Transfer the mixture to a plate. Grease it properly to avoid sticking. Spread the mixture evenly using a spoon. Keep for an hour to set.
Cut into equal square pieces.
Serve or store at room temperature in an air-tight container.