Prepare a loaf pan or small casserole dish by lining it with parchment paper, leaving a slight overhang for easy removal later. Set it aside for the fudge mixture.
Place the chocolate chips in a microwave-safe bowl. Heat them for 25 seconds, then stir thoroughly. Continue heating in 15-second intervals, stirring after each, until the chocolate is completely melted and silky smooth.
Incorporate the sweetened condensed milk into the melted chocolate, adjusting the amount based on your desired fudge consistency. Use more for a softer, creamier fudge, or less for a firmer texture. Stir the mixture until fully combined and glossy.
Pour the chocolate mixture into the prepared dish. Using an offset spatula or the back of a spoon, spread it out evenly, ensuring the surface is smooth.
Sprinkle the crushed peppermint candies evenly over the surface of the fudge. Press them lightly into the still-wet chocolate to secure them in place.
Cover the dish with plastic wrap or foil and refrigerate for a minimum of 2 hours, or ideally overnight, to allow the fudge to firm up completely.
Once set, remove the fudge from the pan by lifting the parchment paper. Slice it into small squares using a sharp knife, then serve and enjoy.