Beat the eggs and water with a little seasoning. Grate cheese coarsely. Chop herbs Steam asparagus for 2–3 minutes or boil for 2 minutes. Half the tomatoes.
To make the omelette:
Melt the butter or oil in a warmed pan and tilt the fat around the edges. Pour in the beaten egg and give a quick stir, tilting the pan to coat well with the egg. Carefully lift the edge of the omelette to let the raw egg run under the cooked part. When almost firm scatter the tomatoes, spring onion, asparagus, herbs and two thirds cheese over. Allow to cook a little more.
Flip over and sprinkle with the remaining cheese. Cook for a further minute and then place below a hot grill until the cheese melts and becomes crispy and golden.
Serve hot with crusty bread or salad