Place the desired filling in the center of the omelette as soon as it has reached the desired degree of doneness. Fold one edge of the omelette over onto the other to cover the filling. If necessary, lift the pan by the handle, tilt and lightly tap the handle so that the omelette will move up from the pan to completely enclose the filling. You can also use a fork to help fold the omelette over. Carefully roll the filled omelette onto a warm plate, seam side down. If necessary, adjust the shape into a neat roll using a clean kitchen towel.