1 roasting pan or other deep oven-ready pan and 6 individual-sized flan molds
Mix the cornstarch with a little bit of milk and stir into a smooth paste. Put the rest of the milk in a small saucepan; add lemon zest and cinnamon sticks. Simmer on very low heat for about 30 minutes (to infuse the milk with the lemon and cinnamon flavour). Remove lemon and cinnamon sticks and discard. Meanwhile, preheat oven to 325 degrees F.
Make the caramel by putting ½ cup of sugar and 2 tbsp. of water in a small saucepan and melting over low heat. Bring to a boil and boil until it turns a dark caramel colour. Remove and pour it on the 6 flan molds.
In a bowl, combine yolks, eggs and remaining sugar. Add cornstarch mixture. Add hot milk, stirring all the time. Pour into flan molds.
Place flan molds in roasting pan. Pour very hot or boiling water around the molds. Place in oven and bake for 40 minutes. Cool. Run a knife round the inside of each mold and reverse each mold into a desert plate. Serve.
Variations: Add crushed almonds or a bit of pure vanilla to create tasty Flan variations.