1.) In a small bowl, beat together eggs, water, salt, and pepper, if desired, until blended. In a 7-10 inch omelet pan or skillet over medium-high heat, heat butter until just hot enough to sizzle a drop of hot water. Pour in egg mixture. Mixture should set immediately at edges.
2.) With inverted pancake turner, carefully push cooked portion at edges toward center so uncooked portions can reach hot pan surface. Tilt pan and move cooked portions as necessary. When top is thickened and no visible liquid egg remains, fill with desired ingredients. With a pancake turner, fold omelet in half.
3.) Place flour tortilla on plate. Invert omelet onto flour tortilla with a quick flip of the wrist or slide from pan onto plate. Roll the flour tortilla, folding in sides as you go. Serve.