In a saucepan, add the sugar, water, and lemon juice. Warm over medium heat, stirring gently until the sugar fully dissolves. Once clear, stop stirring and let it boil until it reaches a deep amber color. Immediately pour the caramel into the flan mold, tilting and swirling to coat the bottom evenly before it sets.
In a mixing bowl, whisk together the eggs and sugar until smooth and well blended. Add the vanilla essence and mix again. Slowly pour in the milk, stirring continuously until the mixture is fully combined. Strain the custard through a fine-mesh sieve directly over the caramel in the mold for a silky texture.
Cover the flan mold tightly with foil and set it gently on the rack. Place the lid on the saucepan and steam over medium heat for 35–40 minutes, or until a toothpick inserted in the center comes out clean.
Remove the flan from the saucepan and let it cool to room temperature. Refrigerate for at least 2 hours until fully set.
To serve, place a plate over the mold and invert the flan onto the plate.
Notes
Watch the Caramel Carefully: I stay close once it starts bubbling; when it turns amber, I take it off right away to avoid bitterness.Strain the Mixture: I always pour the flan mix through a sieve to catch any cooked egg bits and get a smoother texture.Use Foil Tightly: I wrap the mold snugly with foil to keep the steam from dripping into the flan while it cooks.Test with a Toothpick: I check the center with a toothpick; if it comes out clean, I know it’s done.Chill Before Serving: I let the flan rest in the fridge for at least two hours so it firms up and slices neatly.