Prepare the Caramel:

• In a small saucepan over medium heat, combine sugar and water.
• Swirl the pan occasionally (don’t stir) until the sugar dissolves and turns into a golden amber caramel (about 8–10 minutes).
• Quickly pour the caramel into a round 8-inch baking dish or flan mold, tilting it to coat the bottom evenly. Set aside to cool.

Make the Flan Custard:

• Preheat your oven to 350°F (175°C).
• In a large mixing bowl, whisk together the eggs, sweetened condensed milk, evaporated milk, whole milk, and vanilla extract until smooth.
• Strain the mixture through a fine-mesh sieve to remove bubbles for a silky texture.

Assemble and Bake:

• Pour the custard mixture over the hardened caramel in the baking dish.
• Place the baking dish inside a larger pan and add hot water to the outer pan (creating a water bath) until it reaches halfway up the sides of the flan dish.
• Bake for 50–60 minutes, or until the center is just set but slightly jiggly.
• Remove from the oven and let cool at room temperature, then refrigerate for at least 4 hours (preferably overnight).

Unmold and Serve:

• Run a knife around the edges of the flan to loosen it.
• Place a serving plate over the dish and carefully flip it over to release the flan with the caramel sauce on top.
• Slice and enjoy!