Place the milk in a large, heavy-bottom, pot. Over medium heat, bring the milk up to a simmer.
Add the rice and cinnamon. Bring back to a simmer and allow to cook 45-55 minutes on medium low heat, or until it reduces about half. Stir occasionally so the rice and milk don’t scorch on the bottom.
When thick, remove from the heat. Adjust sweetness to taste. Discard the cinnamon stick. Transfer to 4 bowls. Serve warm or cover with plastic wrap, and allow to cool in the fridge.
Meanwhile, in a small pot, add the rhubarb, sugar, and orange zest and juice. Over medium heat, bring to a simmer. Cover and cook for 5 minutes, or until the rhubarb has softened. Remove from the heat and fold in the strawberries. Set aside to cool.
Before serving, Spoon a generous portion of the strawberry rhubarb mixture on top.