Mix all the ingredients thoroughly in a bowl, season.
To shape & bake the croissants
Cut the dough circles into 8 cake-like pieces. Spread the filling evenly on top, leaving a border of approx. 1 cm all the way around. Brush the edges with egg white. Roll the pieces in towards the pointed end. Bend the ends of the croissants inwards and crimp. Place the croissants on a baking tray lined with baking paper, brush with egg yolk.
Approx. 20 mins. in the centre of an oven preheated to 220°C.