In a saucepan, combine the water, rice, and orange peel. Place over medium heat. Simmer for 20-25 minutes, until the rice is very well cooked. Strain the rice and set aside.

Return the same saucepan to medium heat and add 3 cups of the milk (about 700 grams) and the sugar. Bring to a boil.

In a bowl, mix the remaining milk, vanilla, and cornstarch. Stir until the cornstarch is fully dissolved.

Add the cooked rice and the cornstarch mixture to the saucepan. Stir for 3-4 minutes, until the mixture thickens. Remove the orange peel. Divide the pudding into small bowls or pour it all into one container. Cover with plastic wrap and refrigerate until chilled. Sprinkle with cinnamon before serving.