Mix flour, a tablespoon of sugar, salt, eggs and egg yolk. Gradually add milk and mineral water. Let the dough rest for about 15 minutes. Wash the orange, grate dry and tear off the peel as zests.
Then cut the orange into slices. Brush a pan with a little oil. Pour some batter into the pan and spread it thinly on the bottom of the pan by swinging it back and forth. Bake from both sides until golden brown.
Bake another eleven crêpes from the remaining dough. Melt three tablespoons of sugar in a pan until golden brown. Add butter and deglaze with orange juice. Steam orange slices on both sides for one minute.
Remove and stir the zest and liqueur into the sauce. Pull crêpes through the sauce one after the other, fold into quarters and arrange them in the pan like roof tiles. Warm the brandy slightly, pour over the crêpes and flambé.
Arrange crêpes with orange slices on plates.