Make the chocolate mousse, divide it among the half-sphere molds and freeze the tray for 3 hours, ideally overnight.

For the glaze, bloom the gelatin in 20 ml of cold water.

In a saucepan, combine the water, sugar and condensed milk, bring to the first bubbles over low heat, stirring occasionally, and remove from the heat.

Add the bloomed gelatin and stir well. Pour the mixture into the chocolate and stir until smooth and fully melted.

Blend the glaze with an immersion blender until completely smooth. If desired, divide into bowls and tint with gel food coloring. The glaze's working temperature is 35-40°C - warm it over a water bath.

Set up a tray with a wire rack and take out the frozen mousse pieces.

Pour the mirror glaze over the pieces, let it drip evenly, and transfer the pastries with a knife.

Sprinkle any bumps or bare sides with feuilletine, nuts, or chocolate shards.

Refrigerate the pastries until serving. Enjoy!