Remove the zest from an orange and bring to the boil in 0.75l of water. When it starts to boil, remove from the heat and leave to cool.
Break an egg into a large bowl, add a tablespoon of flour and mix. Repeat seven times. Skim off the cooled water and orange zest and pour into the bowl. Whisk to combine. Add 1 teaspoon oil, 1 tablespoon orange blossom, 1 tablespoon vanilla and 3 tablespoons Armagnac (… or 4, 5, or 6!). Mix well.
Leave to stand overnight (in theory, we’re too greedy to wait…). Cook over medium heat, pouring a ladleful into a crêpe pan one at a time.