1 Sift the flour, sugar and salt into a large bowl. Make a well in the centre and add the eggs, milk and 75ml cold water. Begin whisking, gradually incorporating the flour around the edges, then whisk in the butter to make a smooth batter.
2 Warm an 18-20cm non-stick frying pan or crepe pan over a high heat. When really hot, reduce the heat to medium. Add a little butter for cooking, then add just enough batter to coat the base of the pan, swirling it so that it is as thin as possible. Cook for about 1 minute on each side, until golden. Set aside and keep warm. Repeat with the remaining batter to make 8 crepes.
3 To make the sauce, remove the zest from one orange with a zester (or use a vegetable peeler and then slice into very thin strips). Set aside. Finely grate the zest of the remaining orange and the lemon. Squeeze the juices from both oranges and the lemon to give 200ml. Mix the grated zests, juice, sugar, Cointreau and Cognac together in a bowl.
4. Add a quarter of the sauce to a large frying pan. Heat gently for 1-2 minutes or until the sugar has dissolved. Increase the heat and simmer vigorously for 1 minute until slightly thickened and golden in colour. Whisk in the butter, a cube at a time. Once melted and incorporated, whisk in the remaining sauce and reserved zest and simmer for 2-3 minutes, until shiny and thickened.
5. Add one crepe to the pan and let it sit in the sauce for about 10 seconds before folding it into quarters. Push to the edge of the pan and repeat with the remaining crepes. Take to the table then, if using, pour over the hot cognac and cautiously light with a long match to flambé. When the flames disappear, serve immediately on warm plates.