Prepare the Filling
A non-stick omelette pan is essential. Beat the eggs, water, herbs and seasoning together. Heat the pan well, add the butter, pour in the egg mixture. Work quickly, drawing the egg to the centre of the pan as it begins to set. This allows the uncooked mixture to reach the base of the pan. Continue until you have the omelette cooked to your liking.
Place the filling along the centre of the omelette. Starting at the handle, fold over the omelette by 1/3.Slide the omelette down the pan.
Then, with your hand under the handle, tip the omelette onto a warm plate, making the third fold. Sprinkle with finely grated cheese (optional) and serve with mixed salad leaves.