Flatten your white clay into a thick slab. This is going to be the egg 'white'.
Take your yellow clay and roll it out into a snake. This is going to be the egg 'yolk'.
Place the yellow on top of the white slab.
Close the white on the yellow and trim off the excess.
Roll from the centre outwards.
After achieving this, you have my permission to roll out the edges to the same thickness 😁 (I made a Bane reference there...)
It should look like this. Then slice a small piece. This is going to be the 'half hard-boiled egg'.
Cover one of the side (the less prettier one) by pushing the edges upwards, concealing the yolk.
Turn over to the yolk-exposed side and by using a needle tool, outline the yolk and 'scratch' it to form its texture as shown. Ta da~ Use it to decorate tiny dishes or place in small jars :D