Heat a small non-stick skillet over medium-high. Add the tortilla to pan and cook until brown, flipping once, about 2 minutes per side. Set tortilla on a plate and add cheese. Adjust heat to medium.
In a small bowl whisk egg and water until well combined. Season with salt and pepper. Spray the pan with nonstick cooking spray and add egg mixture, swirling to evenly coat pan. Cook for about 2 to 3 minutes until egg is cooked through.
Transfer egg to tortilla. Add spinach and roll tortilla, starting by folding in the sides and then rolling up from the bottom.