In a nonstick skillet heat up extra virgin olive oil over medium heat.

Add the onion and let cook for 30 seconds.

Add the mushrooms, spinach, kale, and diced tomatoes and let cook until heated through and spinach and kale is wilted. About 1-2 minutes.

Salt and Pepper to taste.

Remove pan from heat.

Transfer omelet filling to a plate and set aside.

There should be some olive oil left in the pan. Lightly spray nonstick cooking spray in the pan.

Let the pan cool down.

Reduce stove heat to medium low.

Pour egg whites in the pan and let it cook. Do not stir.

The egg whites will turn a solid white and start to bubble.

Place the filling on one side of the omelet. Save some of the filling to top your omelet.

With a spatula gently fold the empty side of the omelet over the top of the veggie filling.

Transfer omelet to a plate.

Top the omelet with the reserved filling.

Garnish with sliced chives.

Serve immediately.