An oldie but a goodie!
In a very large saucepan simmer milk, rice and 500mL water, mixing often until rice is soft and mixture is the consistency of pouring custard (it will thicken considerably as it cools). This will take a fair while; patience is a virtue.... Remove from heat and mix through condensed milk and vanilla. Let cool then pop in fridge. It will form a skin on top but that's normal (and my favourite part!).
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