1. Preheat the oven to 170°C (340°F).
2. Split the vanilla bean, scrape the seeds, and add both seeds and pod to the milk. Heat just before boiling, then remove from heat.
3. In a large bowl, whisk the yolks, whole egg, and sugar for 2–3 minutes until lightly foamy.
4. Remove the vanilla pod from the milk. Pour a small amount of warm milk over the eggs while whisking quickly to avoid scrambling. Continue adding milk gradually.

Prepare the caramel:

1. Heat the sugar until golden.
2. Add a touch of lemon and pour the caramel into your ramekins before it hardens.

Cooking egg custard :

1. Fill the ramekins : Pour the custard mixture gently over the caramel.
2. Place the ramekins in a baking dish, pour in hot water around them, and bake for 25–30 minutes.
3. Check doneness : The custard should be set around the edges and slightly wobbly in the center. A knife inserted should come out clean.
4. Let cool completely, then refrigerate for at least 2 hours. Unmold just before serving.