Add the oats and water to a blender. Blend until you get a completely smooth batter with no lumps.
Let the batter rest for a few minutes. The oats will absorb excess water and thicken. If it becomes too thick, add a splash of water and stir.
Heat a good non-stick (teflon) pan well over medium heat — do not add any oil.
Pour the batter with a ladle onto the hot pan in your desired size. Keep the flatbreads relatively thin so the center cooks properly.
Reduce heat slightly. Flip the lepinja every 10 seconds for even cooking.
Cook for 5–10 minutes total (depending on thickness), flipping often, until the surface looks dry and the center is fully cooked.
Remove from the pan. While still warm, cut the flatbread with scissors. If the inside is not dry enough, cut it open to create a pocket, then return briefly to the pan to dry it out a bit more.
Fill with sweet or savory fillings of your choice and enjoy!