Peel and roughly chop the carrots.
Grate the zest off the oranges and squeeze out the juice.
Cook the carrots in the orange juice with the zest until they are completely tender.
After cooking zap them to a pulp, you should get about 750g/1lb 11oz of pulp.
Now add the jam sugar, grated zest of lemon and the lemon juice and those chopped up pistachios.
Heat gently to dissolve the sugar and raise to a boil. Bubble away until you reach your setting point (that chilled saucer in the freezer for 5 minutes teaspoon of the jam on it and back to fridge for 5 mins to see if it sets enough) and then spoon this gorgeously bright golden zingy jam into sterilised jars and store in the fridge.