In a saucepan, combine 100 g granulated sugar, 30 ml water, and 1 tsp lemon juice for the caramel. Heat gently without stirring until it turns a deep golden color. Pour the hot caramel into the base of your flan mold, swirling to coat the bottom evenly. Let it set.
In another saucepan, combine 250 g granulated sugar and 250 g water. Bring the mixture to a boil over medium heat until it reaches a temperature of about 221°F(105°C) to 223°F (106°C) to obtain a strand-like syrup. Let the syrup cool to room temperature.
In a mixing bowl, whisk together the 6 egg yolks and 1 egg until smooth. Gradually add the cooled syrup to the eggs, whisking gently to combine without creating foam. Strain the mixture through a fine sieve into the caramel-lined mold to ensure a smooth texture.
Cover the mold with foil and place it in a larger baking dish filled with hot water for a bain-marie. Bake at 356°F (180°C) or 320°F (160°C) for fan-forced for 40 minutes, or until just set and a toothpick comes out clean. Remove from the oven and let cool completely. Chill in the fridge for at least 6 hours or overnight.
To serve, run a knife around the edges and invert onto a plate to release the flan with the caramel on top.
Notes
Watch the Syrup Temperature: I always use a thermometer and stop cooking the syrup once it hits 221°F (105°C). That way, I get the perfect strand-like texture without overcooking it.Whisk Gently, Not Vigorously: I whisk just enough to blend everything without creating bubbles. It keeps the flan smooth and free of foam.Strain for a Silky Texture: I like to strain the egg mixture before pouring it into the mold; it makes a big difference in how silky the flan turns out.Chill Overnight if You Can: I usually leave it in the fridge overnight. It sets perfectly and is so much easier to unmold the next day.