Melt two thirds of the total quantity of GUANAJA 70% (400g) chocolate in a bain-marie or in the microwave.
Increase the temperature to 120-130°F (50-55°C). Once this temperature has been reached, add the remaining third of the chocolate.
Start mixing by hand, then using an immersion blender. Be careful not to incorporate any air bubbles.
Check that the temperature of the chocolate has reached 88-90°F (31-32°C). The chocolate is now tempered. Make sure you keep the chocolate at this temperature while you work with it. If you need to, use a hairdryer to reheat its surface.
Immediately pour the tempered chocolate into 2 half-sphere molds. Leave to set at room temperature for 2 hours. Turn out each half-sphere, then stick them together using the bottom of a heated saucepan.
Heat up the end of a 10mm plain round nozzle using a hair dryer then pierce the chocolate spheres one by one in order to fill them. Set them aside to fill them with praliné or coconut ganache later.