The butter is allowed to soften at room temperature. Messi with sifted flour, rum, 2 tbsp water and a little salt. The dough is made ball, which is placed in a closed container for 1 hour in refrigerator. Peel the onion, cut into thin slices, put it in a deep dish, pour in as much water as lightly cover it, add the oil and sugar, add salt and sprinkle with pepper. At first the onion boil on medium heat, and then - on low. Hold on the fire until the water evaporates it red. Allow to cool. Remove the dough from the refrigerator and spread in a large pan, sprinkled with flour. Attention is 1/3 of the dough and the rest of the dough was transferred into a rectangular pan and spread so as to cover the bottom. Prick a few places with a fork and spread the onions on top. Roll out dough and separated from him cut strips of width 1 cm. The bands form ribbons, which are mounted on the onions. Mix egg yolks with a pinch of salt and 2 tbsp water and smeared onion pastry top. Bake in preheated moderate oven, until the dough is golden. Onion pastry is served cold.