In a medium bowl, break the eggs then whisk until the whites and yolks are combined. Season with a pinch of salt.
Melt the butter over MEDIUM heat in an 8-inch nonstick skillet. Pour the beaten eggs into the skillet and reduce to LOW heat.
Cook the eggs without stirring until the edges start to set, about 10 seconds. Use a spatula to push the cooked egg from the edge to the centre of the skillet. Tilt the skillet if needed to let the uncooked egg flow to the outer edges.
Gently fold the omelette in half then carefully slide onto a plate. Season with black pepper and garnish with chopped scallions.