Butter a 9″×13″ baking pan and line with parchment to overhang sides.
In a metal bowl or top of double boiler, add all ingredients except salt.
Set over pot of gently simmering water, stirring constantly until chocolate has completely melted. Mixture will be very thick.
Spread into lined pan. Allow to cool to room temperature, then cut into squares.
Sprinkle lightly with sea salt and garnish with arils.