Put the rice together with the milk in a double bottom pan. Split the vanilla pod and scrape the seeds and add them both to the rice. Gently bring to the boil, stirring constantly. Bring to the simmer and continue cooking for further 45 minutes, until the rice has absorbed all the milk. Remove from the heat, mix in the sugar, allow to cool completely. Remove the vanilla pod from the rice, gently fold in the cream and the flaked nuts. Divide the rice pudding into serving glasses. Chill well before serving. To prepare the sauce, dilute the corn flour with two table spoons of water. Place the cherries with the lemon juice, sugar, vanilla and the remaining water, bring gently to the boil. Thicken the sauce with the corn flour and cook until it thickens. Serve the hot sauce over the rice puddings.