Heat 1/2 Tbsp oil in a small frying pan over medium heat. Add onions and mushrooms and saute until onions become clear. Add spinach, bell peppers, and tomatoes. When spinach has wilted, remove from heat and cover with lid or foil to keep warm.

Crack the eggs into a mixing bowl and whisk until eggs become light yellow in color. Set aside. Pour 1/2 Tbsp oil into an 8" pan and swirl around until the pan is evenly coated with oil. Put the pan on the stove over medium-low heat.

While oil is heating quickly add water, dill, salt, and pepper to the eggs and beat vigorously until the eggs become light and airy. When the oil becomes wavy and hot, slowly pour the eggs into the pan. Once the eggs are in the pan, do not stir! Let them just sit and start to bubble up a little bit.

When the bottom of the eggs begin to set a little bit, use a spatula to gently push one edge of the egg into the center of the pan while tilting the pan to allow the still liquid egg to flow in underneath. Repeat with the other edges, until there's no liquid left.

Your eggs should now resemble a bright yellow pancake, which should easily slide around on the nonstick surface. If it sticks at all, loosen it with your spatula.

Now gently flip the egg pancake over, using your spatula to ease it over if necessary. Cook for another few seconds, or until there is no uncooked egg left. DO NOT OVERCOOK!

Add cheese to the middle of the omelet. Quickly fold the omelet as if folding a piece of paper in half. You may keep the omelet in the pan until the cheese is melted, flipping over if necessary.

Top with sesame seeds and cilantro.