Mix the flour and salt in a bowl, create a well in the middle. Whisk the milk, water, mustard, eggs and oil, gradually pour into the well while whisking, continue whisking until the batter is smooth. Cover and leave to stand at room temperature for approx. 30 mins.
Heat the oil in a non-stick frying pan. Pour enough batter into the pan to thinly cover the base. Scatter a few herbs on top. Reduce the heat. Once the underside is cooked and separates from the pan, turn the omelette and finish cooking, then remove. Repeat these steps with the remainder of the batter.
Combine the cream cheese with all the other ingredients up to and including the pepper, mix in the herbs.
Spread the filling over the omelettes, top with the salmon. Roll up the omelettes tightly, cut into rolls approx. 2 cm thick, insert toothpicks if necessary.