Separate the eggs. In one bowl, add the sugar to the yolks and beat until thick and lemon-coloured, then stir in the orange rind. In another bowl, whisk the egg white until just stiff and fold them into the egg yolk mixture carefully, using a metal spoon.
Preheat the grill. Heat the butter in a 7-inch frying pan until foaming, and pour in the mixture. Cook over a low heat until the underside of the omelette is golden (do not attempt to stir it; in fact, apart from peeking at the underside with a palette knife, leave it entirely alone).
Transfer the pan to sit under the grill and cook for 2 minutes, or until the surface is golden brown. While this is happening, stir together the jam and orange juice. When the omelette is cooked, pour the jam mixture over one half and fold the other half over. Dust with a little sugar and serve immediately.
From the Dinner Co-op