In a small saucepan, melt the chocolate and butter together over low heat.
Once melted, remove from heat, stir through the stevia and allow to cool.
While the chocolate mixture is cooling, prepare the eggs.
Separate the eggs, placing the yolks and whites into two separate bowls.
Once the chocolate mixture has cooled a little whisk the mixture through the yolks.
Beat the egg whites until they form thick white peaks.
Fold the egg whites gently through the chocolate mixture until completely combined.
Place into the fridge to set for a few hours and enjoy!