Place 1 and 1⁄2 cups of milk in a saucepan over low heat with the sugar or panela. Separately dissolve the starch in 1⁄2 cup of milk. Add the cornstarch mixture with the cloves, cinnamon sticks, rose water and dried blueberries to the milk that should be boiling. Stir slowly for 15 minutes when this list is removed from the heat and the cloves and cinnamon are removed. Pour into a container and let cool for at least an hour. Put the blueberries with the water, sugar and water in a pot. Cook over medium heat, stirring constantly, until mixture thickens. Add the cornstarch dissolved in a tablespoon of water and cook for another 3 to 5 minutes or until the fruits soften a little. Remove from the fire and let cool. Serve the custard with the blueberry jam.