Ultimate Stuffed Omelette with Creamy Vegetable Filling

This omelette (well, similar versions) is served as breakfast in many casual diners in Hong Kong. The filling of this omelette obviously can be varied, depending on your likings or what leftovers you have in your fridge at the time. It's very easy and fast to make. The basic, yet MOST IMPORTANT ingredients for the filling is onion and a few spoonfuls of cream of mushroom (canned soup for convenience, or the homemade kind if you have the time, the thicker the better). It might look super easy to you, but the result is amazing. Very, very tasty! The rest of the ingredients would be completely your choice. Chopped chicken or ham and cheese would also be great additions to this delicious dish!

So, here we go, this is how I made the omelette pictured above:
Ingredients:
2-3 large eggs
a few baby spinach leaves (about 10 or so)
2 tablespoons of sweet corn (drained)
3 white mushrooms (washed, dried and chopped)
1/2 small yellow onion (chopped)
1 big tablespoonful of cream of mushroom soup (canned) 
1 tablespoon of chunky, chopped tomato (canned)
1 tablespoon of olive oil

Step 1: Saute onion with a little oil over medium heat for about 5 minutes. Turn heat off, put cooked onion in a small bowl.

Step 2: Whisk eggs in a medium bowl. Over medium heat in a large non-stick pan, pour over the egg mixture, Move the pan around to get egg over the whole surface. Cook for a few minutes.

Step 3: Add cooked onion, cream soup, vegetable (except tomato) one by one onto 1/2 of the egg. Cook for about 3 minutes.

Step 4: Just using a flat spatula, flip the side of the egg that does not have filling to close the omelette. Overflowing a little is ok, it all depends on how you like it. Cook for another 3-5 minutes.

Step 5: Put the chopped tomato over the omelette after transferring to a big plate. Serve immediately!