Bring the heavy cream to a simmer over medium heat in a small pan. While it is heating combine the sugar and lemon juice in a medium pan. Put it over medium heat and cook, stirring constantly, until it reaches a light amber color. Carefully pour the cream into the sugar (it can splatter), whisking constantly. Continue to cook and whisk for another 1 or 2 minutes. Let the caramel cool for a few minutes, then drop it by the tablespoonful onto a baking sheet lined with waxed paper. Let cool a few more minutes, then drop a small mound of salmon roe on top of each caramel. Serve.