Pre-heat the oven to 200 degrees.
Break the white chocolate into squares, and place them in a glass oven-safe bowl. Place the bowl in the oven and heat until the chocolate has melted. This usually takes about 10 minutes, stirring once.
Once melted, add about 20 drops of green food coloring and mix. Pour the melted chocolate over a large flat baking sheet, and using a flat pastry scraper, spread the mixture as thinly as possible over the sheet. You want it to be thin enough, but not see through.
Place the baking sheet in the refrigerator for 5 minutes. Press your finger moderately onto the chocolate: if you make an indent, continue to refrigerate until you can press your finger onto the chocolate and there is no imprint. Remove the baking sheet from the fridge.
Holding your pastry scraper at a 45 degree angle, press down on the chocolate and push in one direction. If the chocolate is too soft, it will not curl. If it is too hard, it will splinter. See the 'TIPS' section below the recipe to see what to do if either of these things happens.
To get 'tree' shapes, keep one end of the scraper in one spot, and push the rest of the scraper in a half circle motion. See images above for reference.
Once you have enough chocolate curls made, place them in the refrigerator for at least 10 minutes before sticking them into the mousse pie.
Once the spirals are placed in the mousse pie, you have the option of sprinkling confectioners sugar over the top for a 'snow' look!