Add 1 3/5 cup (283.5 g) of bittersweet chocolate chips and 14floz (410ml) of sweetened condensed milk to a medium saucepan. Adjust the stovetop temperature to a medium heat. Stir the chocolate chips and condensed milk continuously as it cooks. Keep cooking the ingredients until the chocolate chips have melted and the ingredients have combined. Remove the saucepan from the heat once the chocolate has melted. Leave the baking dish in the refrigerator until it solidifies. After 1 hour, press on the mixture gently with a fork or the back of a spoon to check that it feels firm. Alternatively, you can let the mixture set at room temperature rather than in the refrigerator. However, it will take longer to set this way. Depending on the size of the baking dish that you used, the fudge may take up to 3 hours to set. Remove the fudge from the baking dish by lifting up the overhanging parchment paper. Place the fudge onto a chopping board to slice it. You can store any leftover rocky road fudge in an airtight container in the refrigerator for up to 3 weeks.

Summary:
Cook the chocolate chips and sweetened condensed milk for 2-3 minutes. Chill the mixture in the refrigerator for 1 hour until it's set. Slice the fudge into 1in (2.5cm) squares.