• Add the gelatin to a small bowl and pour over just enough cold water to cover it. Leave to bloom for 5–10 minutes until softened.
  
• Add the milk, cream and sugar to a saucepan set over medium heat. Warm gently, stirring occasionally, until the sugar has dissolved and the mixture is steaming hot but not boiling.
  
• Remove the pan from the heat and stir in the pistachio cream until fully melted and smooth.
• Add the gelatin to the warm cream mixture. Whisk well until completely dissolved.
  
• Divide the mixture evenly between moulds or ramekins. Leave to cool at room temperature, then transfer to the fridge to set for at least 6 hours, or ideally overnight.

To unmould the panna cotta

• Fill a bowl with hot tap water.
• Run a thin knife gently around the edge of the panna cotta to loosen it slightly, then dip the base of the mould into the hot water for about 20–30 seconds (do not let the water rise above the rim).
• Remove from the water, place a serving plate on top of the mould and invert. Give it a gentle shake or tap until the panna cotta releases onto the plate.
• Remove from the water and place of a plate. Give the panna cotta a firm shake until you hear it unmould.