Step 1: Prepare the Sago Pudding

1. In a medium-sized saucepan, combine the sago pearls, milk, and cinnamon stick. Simmer over low heat, stirring frequently, for about 20 minutes until the sago becomes translucent.

2. In a separate bowl, whisk together sugar and egg yolks. Gradually add a spoonful of the warm sago mixture to temper the eggs, then stir the egg mixture back into the saucepan.

3. Continue cooking for another 5 minutes, stirring constantly to prevent the eggs from scrambling.

4. Remove the cinnamon stick, then stir in the butter, vanilla extract, and a pinch of salt for added flavor. Once the pudding is creamy and well-mixed, divide it evenly into ramekins and set aside.

Step 2: Make the Lemon Curd

1. In a heatproof bowl, whisk together the lemon juice, lemon zest, sugar, and egg yolks.

2. Set the bowl over a saucepan of simmering water (double boiler method), ensuring the bowl does not touch the water. Continuously whisk the mixture for about 10 minutes until it thickens to a custard-like consistency.

3. Remove from the heat and stir in the unsalted butter until smooth. Spoon a generous layer of lemon curd over each ramekin of sago pudding.

Step 3: Prepare the Meringue

1. In a clean bowl, whisk the egg whites with cream of tartar until soft peaks form.

2. Gradually add caster sugar, whisking continuously until the meringue becomes stiff and glossy.

3. Spoon or pipe the meringue over the lemon curd layer, covering it completely.

Step 4: Bake & Serve

1. Preheat your oven to 180°C (350°F).

2. Place the puddings in the oven and bake for about 10 minutes, or until the meringue is lightly golden and crispy on top.

3. Allow the puddings to cool slightly before serving. Enjoy!