Put the lemon juice, sugar, sliced vanilla pod and cinnamon stick in a large pan. Pour 0.5 liters of water and bring to the boil. Put the pears in the pan with the cut side facing down and cook for 12-15 minutes, drizzling with the cooking liquid from time to time. Remove the pears from the brew and let them cool down.
Melt the couverture in a water bath.
Spread the vanilla ice cream on dessert plates, serve with 2 pear halves each, pour the hot couverture over them and serve with a little whipped cream.