Spray skillet with cooking spray and wipe excess with paper towel. Heat skillet on LOW then add butter, being careful not to brown. Make sure melted butter covers bottom of skillet. Note: I use a 10-inch iron skillet.
Pour egg mixture into heated skillet and butter. Do not stir until bottom of eggs appear set. Cooking over low/med heat, gently fold over and stir occasionally until eggs are done but not dry.
Sprinkle lightly with salt and serve while warm. Recipe may be doubled.