Creating the perfect chilled mint chocolate parfait involves layering and chilling each component to achieve the right texture and flavor. Follow these step-by-step instructions to create your own masterpiece:

Step 1: Prepare the Biscuit Layer

1. In a mixing bowl, combine the crushed biscuits, melted butter, and granulated sugar.
2. Stir until the mixture resembles wet sand.
3. Press a layer of the biscuit mixture into the bottom of each serving glass or dish. Use the back of a spoon to compact the mixture evenly.
4. Place the glasses in the refrigerator to set while you prepare the other layers.

Step 2: Make the Chocolate Layer

1. In a saucepan over low heat, combine the chocolate chips and heavy cream.
2. Stir continuously until the chocolate is fully melted and the mixture is smooth.
3. Allow the chocolate mixture to cool slightly, then pour a layer over the biscuit base in each glass.
4. Return the glasses to the refrigerator to allow the chocolate layer to set.

Step 3: Prepare the Mint Cream Layer

1. In a chilled mixing bowl, whisk the heavy cream until soft peaks form.
2. Add the powdered sugar and peppermint extract, continuing to whisk until stiff peaks form.
3. If desired, add a few drops of green food coloring and fold gently to incorporate.
4. Spoon or pipe the mint cream over the chocolate layer in each glass.
5. Chill the parfaits in the refrigerator for at least 2 hours, or until set.

Step 4: Garnish and Serve

1. Just before serving, garnish each parfait with fresh mint leaves and chocolate shavings or chips.
2. Serve chilled and enjoy!