Step 1 Combine the cream and sugar in a small saucepan. Bring just to a simmer over medium-low heat and remove from the heat. Let stand until just cool, stirring occasionally, about 20 minutes.
Step 2 Stir in the lemon juice. Blend well. Divide between 2 goblets or small serving dishes and chill until firm, at least 4 hours and preferably overnight. Garnish with a sprig of mint, if desired, before serving.