Bring the milk and honey to the boil and let it cool down for about 10 minutes. Mix the egg yolk with the honey milk. Whip over a hot water bath until the mixture is thick and creamy. Cool over a cold water bath, stirring several times.
Whip the cream with the whisk of the hand mixer until stiff and fold into the cream. Rinse a box mould (approx. 11 x 25 cm; 1.25 litres) with water, line with foil and pour in parfait mixture.
Cover with foil and place in the freezer for 8-10 hours.
Wash 2 organic oranges, grate them dry and peel them in zests. Peel all oranges so that the white skin is completely removed. Remove the fillets with a sharp knife between the parting skins.
Squeeze the juice out of the separating skins and collect it. Caramelise the sugar in a pot, deglaze with orange juice. Add orange fillets and zests. Let simmer at low heat until the sugar is dissolved.
Pour into a bowl, allow to cool and chill.
Chop the pistachios. Turn the parfait out of the mould, remove the foil. Put parfait on a plate, cut into slices and serve with oranges and pistachios.