Break chocolate into small pieces and place in a heatproof bowl. Place the bowl above a pan with simmering water and melt the chocolate completely.
Transfer chocolate to a measuring jug and slowly pour into the mould so each compartment is full. Gently shake the mould to remove any air bubbles, then freeze for 10 minutes.
Meanwhile, grate the regal icing and put 100g (3.5oz) in a bowl. Set aside the remaining 150g (5.3oz) in a separate bowl.
Add the sugar and water to a pan over a low heat until the sugar is completely dissolved.
Add the turmeric and vanilla extract to the 100g (3.5oz) of regal icing, along with a few spoons of the sugary water. Mix until smooth. Add more of the liquid if required.
Add the remaining sugary water to the 150g (5.3oz) of regal icing and mix until smooth.
Remove the mould from the freezer and spoon out the middle of each half using a teaspoon. Pipe the plain icing mix into two thirds of each egg half and pipe the turmeric icing mix into the remaining third.
Freeze for at least a further 20 minutes (or longer depending on how soon you want to eat the eggs).
Remove the mould from the freezer and push out egg halves.
Dip the end of a chopstick in the remainder of the melted chocolate and brush the stick over the edges of each egg half. Stick two halves together to form an egg.
Leave to soften until ready for eating!
