Break the chocolate into small pieces, and melt in a heatproof bowl set over a pot of simmering water. Add the milk and stir until the chocolate is completely melted. Remove the bowl from the heat, and mix in egg yolks until well incorporated.
In a large bowl with the use of a hand mixer, bring the egg whites and salt to soft peaks. With the mixer running, add the sugar and beat until stiff peaks.
Add one-fourth of the whites to the chocolate mixture and fold until fully combined, then fold in the rest of the whites until just fully incorporated. Pour mixture into ramekins or molds and let set at least 2 hours or up to 3 days in the fridge.