Step 2
In 4-quart nonstick saucepan, heat sweetened condensed milk and 1 tablespoon unsalted butter to boiling, stirring constantly with wooden spoon. Reduce heat to medium-low and continue to cook, stirring constantly, 10 to 15 minutes or until thick and shiny and starts to pull away from bottom and sides of pan. You will know mixture is ready when you tilt pan and mixture slides down easily. Stir in pecans. Transfer mixture to greased plate. Cool completely.