Whisk together eggs, water, sugar and flour; set aside.
Combine ricotta cheese, grated orange rind and chocolate chips.
Microwave on Medium power (50%) for 50 seconds; set aside.
Spray a 10-inch (25 cm) non stick skillet with cooking spray. Heat skillet over medium high heat.
Pour in egg mixture. As mixture sets at the edges, with spatula, gently lift cooked portion to allow uncooked egg to flow underneath. Cook until bottom and top are set.
Slide onto a warm plate.
Spread ricotta cheese mixture on omelette.
Roll up omelette.
Drizzle with melted chocolate, if desired.Cut diagonally in half.