Creamy Rice Pudding with Rhubarb Sauce

• about 1 tablespoon butter
• 75 g/3 oz round-grain rice

Butter the pie dish liberally, scatter the rice in the bottom of it, pour in the milk and add the sugar and vanilla essence. Bake in a cool oven (about 150°C, 300°F, Gas Mark 2) for 4 hours or so or until the rice has absorbed the milk, a good brown ski