The definition of perfect scrambled eggs differs from person to person and generally has to do with the size of the curd and the degree of wet creaminess, but there is one point on which we can all agree: Nobody wants dry, tough eggs. Cooked correctly, the proteins in an egg form a net, holding in moisture that later steams into light, fluffy curds. But too much heat and time cause the proteins to coil so tightly that moisture is wrung out.The solution: Cook low and slow, moving the eggs constantly in the pan; this maintains the creamy texture. Heat butter in a pan over medium-low heat just until foaming; then add beaten eggs. (You don't need to add water to your eggs—it needlessly prolongs the process.) Use a wooden spoon to drag uncooked eggs to the center of the pan. Dragging the spoon, rather than stirring vigorously, creates medium-sized curds—perfect for light, fluffy eggs. If you like smaller curds, gently break the mixture more. Make sure to remove the pan from the heat when the eggs are still glossy, or slightly undercooked; residual heat will finish cooking them.