Melt the chocolate and butter together in a heat proof bowl over a pot of simmering water. Mix to combine and once melted turn off the flame.

Wash and peel the oranges removing as much of the pith as possible. Separate them into perfect slices and pat them dry with a paper towel.

Take each orange slice and dip it in the chocolate. Pick it up with a pair of tongs and allow the excess chocolate to drain. Transfer each orange slice, one by one to a parchment lined baking sheet. Sprinkle with a few flakes of sea salt and place in the refrigerator for the chocolate to set.

Arrange on a serving platter and serve.