Stuffed omelette

Three eggs (or half carton of egg white)Two tbsp. all purpose flowerOne fourth cup milk Salt to tasteOil spray
For filling
5-6 mushrooms
One medium sized onion
One small tomato
2-3 cloves of garlic
Half cup cheese (I used shredded Mexican blend)
Salt to taste
Two tbsp. oil (I used olive oil)

The filling
Cut the mushroom into this slices. Finely chop the onion. Chop the tomato, and garlic. Heat one tbsp. of oil in a heavy bottomed pan , and add all the vegetables. Fry for few minutes covering the pan. When water starts oozing out of from the mushrooms, uncover the pan, and continuing frying under medium heat. When the mushrooms are soft increase the heat to dry up the vegetables. Add cheese and mix well. Keep the stuffing aside. 
The omellette
In big bowl whisk egg (or egg white), milk,and salt.  Grease a large frying pan with cooking spray and heat in medium heat. Add half of the batter, and spread all over the pan. Fry until the batter almost dry up on the pan. Then flip and fry the other side.On one half add half of the staffing of the omelette. Fold the other half over it. Put the omelette on a plate, serve hot.