Combine 1 tablespoon oregano, salt, pepper, and eggs in a small bowl, stirring with a whisk. Stir in half of crumbled potato chips. Return pan to medium heat. Add remaining 1 tablespoon oil to pan; swirl to coat. Add egg mixture; cook 1 minute. Lift edges of omelet with a rubber spatula, tilting pan to roll uncooked egg onto bottom of pan. Cook 1 minute or until center just begins to set but is still very soft. Arrange onion mixture evenly over center of omelet. Run spatula around edges and under omelet to loosen from the pan; fold in half. Slide omelet onto a plate; cut in half. Sprinkle halves evenly with remaining 1 tablespoon oregano and remaining potato chips.
