Pour half a can of sweetened condensed milk into a mixing bowl. Heat about 1/4 cup (60 ml) boiling water and add it to the condensed milk, stirring well to combine and slightly thin the milk. Add the 2 cups (480 ml) whole milk to the mixture and stir until smooth.

Separate 3 of the eggs, keeping only the yolks. For the remaining 3 eggs, use both the whites and yolks. Add all the prepared eggs to the milk mixture. Gently whisk until the mixture is smooth and well combined. Strain the mixture through a fine mesh sieve to remove any lumps for a silky texture. Add a few drops of lemon juice to help reduce the eggy smell. Chill the mixture in the refrigerator for about 30 minutes to let it settle.

In a small saucepan, combine 1/2 cup (100 grams) granulated sugar with a little water. Heat over medium heat until the sugar dissolves. When the sugar starts to turn a light amber color, lower the heat and let it simmer gently. Do not stir with a spoon; instead, gently swirl the pan to mix. Once the caramel turns a slightly deeper brown, add a few drops of lemon juice and remove from heat. Spoon the caramel into the bottom of your flan molds.

Pour the chilled egg and milk mixture into the molds over the caramel. Cover the molds and steam in a water bath for about 20-30 minutes, depending on the size of your molds, until set.