Preparation

1. Preheat oven to 350°F.
2. Melt sugar over medium heat, continuously stirring until brown caramel sauce forms. Pour warm sauce into bottom of 9-inch tube pan, swirling to coat.
3. Combine condensed milk and fresh milk in large bowl. Beat in eggs, and stir in cornstarch and vanilla.
4. Pour mixture into caramel-lined pan, and place dish inside a larger pan to make a water bath.
5. Boil enough water to fill larger pan to a depth of about one-inch, creating a moist, indirect heat source around the smaller dish. This water bath will prevent a rubbery texture.
6. Bake in preheated oven 50 to 60 minutes, until center is set but still jiggles.
7. Cool flan completely, and then refrigerate at least one hour.
8. To serve: use a knife to loosen sides of flan, then gently flip onto a serving platter, and allow caramel sauce to cover it. Slice into serving-size pieces.