First, use non-stick spray to spray the inside of an 8 inch square pan or loaf pan. Then the pan with parchment paper. Set aside.
Next, combine the chocolate chips and sweetened condensed milk in a medium size saucepan and cook over low heat. Make sure you stir the mixture consistently. It's done when it's melted and smooth which should only take a few minutes.
Take the saucepan off the heat and pour the fudge mixture into the prepared pan you set aside earlier. Use an offset spatula to spread the fudge out evenly.
Toss the crushed peppermints over top now if serving quickly or add them later if leaving in the fridge for more than 24 hours. Crushed peppermints can soften if left in the fridge too long.
Pop the pan in the fridge until the fudge firms up.
Press crushed peppermints into the top before slicing.