In a high-speed blender, combine rolled oats and water. Blend until the mixture is smooth and creamy.
The mixture will be very thin. Let it rest for 20 minutes to allow the oats to absorb the water and thicken slightly.
Heat a non-stick pan over medium heat. Lightly oil the pan. Pour about ½ cup of the oat mixture into the pan and rotate it in a circular shape to spread out the batter evenly. Cook for 2 minutes on one side, until golden brown.
Flip the tortilla and cook for 2 minutes on the other side.
Flip the tortilla again and cook for 1 minute on one side. Flip one final time and cook for 1 minute on the other side. This extra cooking time is essential for the tortilla to become soft and airy. Repeat with the rest of the batter.
