Blend the rice flour with 4 tablespoons of the milk. Place the remaining milk and the diluted rice flour in a heavy-based saucepan, stir well and bring to simmering point. Cover and cook gently for around 10 minutes, stirring regularly.
Add the caster sugar and orange-flower water, stir well and take the pan off the heat.
Place the creamed rice in small serving bowls and leave to cool. Sprinkle with chopped pistachios and serve at room temperature.