Finely chop 500g of dark couverture chocolate.

Place two-thirds of the chocolate in a heatproof bowl over a saucepan of simmering water, ensuring the bowl does not touch the water.

Heat the chocolate while stirring until it reaches a temperature of 45-50°C (113-122°F).

Remove the bowl from the heat and gradually stir in the remaining third of the chopped chocolate to seed it.

Continue stirring until the temperature drops to 27-28°C (81-82°F).

Briefly return the bowl to the heat for a few seconds to reach the working temperature of 31-32°C (88-90°F).

Polish the interior of the egg molds with a clean cotton wool ball.

Ladle the tempered chocolate into the molds, swirling to coat the entire surface and tapping the sides to release air bubbles.

Invert the molds over a sheet of parchment paper to allow excess chocolate to drip out, leaving a thin shell.

Scrape the mold surface clean with a bench scraper and refrigerate for 20 minutes until the chocolate contracts and releases.

Carefully remove the chocolate halves from the molds.

Briefly place the edges of the halves against a warm baking sheet to melt them slightly, then press two halves together to seal.