Preheat the oven to 160°C (320°F). Arrange 6 ramekins in a deep baking dish.
To make the caramel, put the sugar in a small pan. Place over low heat and watch the sugar carefully as it begins to melt, then simmer, and finally, turn amber. Resist the urge to stir but just let it do its thing, at least until the very end, when a swirl of the pan can help. When it begins to color, it will do so very quickly so be ready to remove it from the heat at deep amber — too dark and it will be bitter. When the caramel is the ideal color, remove the pan from the heat, and stir in 1 ½ tablespoon water, taking care as it may bubble up.
Immediately pour the hot caramel into the ramekins. It solidifies very quickly, so don’t worry if it doesn’t cover the bottom of the ramekin — it will all come out perfectly in the end. Set aside.
Warm the milk and sugar in a saucepan over medium heat. As soon as you can see bubbles around the edge and the milk is steaming, take it off the heat before it can simmer. Add the soy sauce and have a taste — if you would like a stronger soy sauce flavor, add another teaspoon. Leave to cool slightly.
Whisk the eggs gently by hand in a bowl. Once the milk has cooled to warm bath temperature, add it to the eggs. To ensure a smooth consistency and ease when pouring, strain the custard through a fine-mesh sieve into a 4-cup glass measuring cup with a spout. Pour the custard into the ramekins.
Fill the baking dish with hot water and put in the oven. Bake for 25 minutes or until the custard has set — it will be wobbly to the touch but the top will be lightly browned.
Cool completely before serving, or they can be chilled until needed. They will keep in the fridge for 3 days.
To serve, run a knife around the edge of the ramekin and hold a plate over the top, then flip everything over in one swift movement so the pudding turns out.