Melt the fat. Mix eggs, flour, milk and a pinch of salt. Stir in the fat and let it swell for 15 minutes. Peel and finely chop the onions. Mix sour cream and egg yolk. Fold in onions and smoked ham.
Season with salt, pepper and caraway seeds. Heat the clarified butter in portions in a large pan. Bake three pancakes (about twelve centimetres in diameter) from the dough 4 times in succession.
Fill with the cream and roll up. Pour into four greased ramekins and sprinkle with cheese. Bake in the preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) for ten minutes.
Sprinkle with chives.