In a saucepan, bring water, lemon peel, butter and salt to a boil. When it is boiling add the rice and reduce heat to a simmer for about 25 minutes or until almost all the water has been absorbed then add the hot milk. Continue to let simmer for about 5 minutes then add the sugar.
In a separate bowl, beat the egg yolks together and add a few tablespoons of the rice mixture to temper the eggs. Add the egg mixture quickly into the saucepan. Let the rice continue to simmer for about 10 minutes to allow rice to thicken. The rice should not completely absorb the liquid, it should form a nice creamy consistency. Remove lemon peel and transfer to one large serving dish or small cups and garnish with cinnamon.