Mix flour, 1 tablespoon pistachios, 1 tablespoon sugar, 1 pinch of salt and milk. Stir in egg and let the dough swell for about 15 minutes.
In the meantime, wash organic orange hot, dab dry and peel off some of the peel into strips. Squeeze the orange. Peel the remaining orange so that the white skin is completely removed. Cut the orange into slices.
Stir mineral water into the dough. Heat a coated pan and brush with oil. Pour in 1/4 of the dough and spread thinly. Bake from both sides until golden brown. Bake 3 more crêpes from the remaining dough.
Melt 3 tablespoons of sugar in the pan. Add butter. Stir in orange juice, zest and liqueur. Steam orange slices for about 2 minutes. Fold crêpes together and arrange on plates with oranges and sauce.
Sprinkle with remaining pistachios.