Rich Custard - (Tocino De Cielo)

Heat 1/2 cup sugar in a saucepan until it thickens and turn light brown. Line a 10-inch ring mold with the caramel.

Heat 2 1/2 cups sugar with water and lemon peel in a saucepan over a slow fire. Simmer for approximately 30 minutes. Test frequently by dipping a tablespoon in the syrup and holding it vertically over the pan. Wait for the last drop: the syrup is done as soon as a thin, short thread forms at the end of the last drop.

Remove from fire and let cool to room temperature. In a large bowl, mix the yolks and the egg just enough to blend (do not beat). Continuing to stir eggs, gradually pour in the cooled syrup. Strain the mixture. Put the caramelized mold on top of a plate in a pan of water which is hot but not boiling. (The purpose of the plate is to keep the mold from touching the hot bottom surface.)

Add water to one-third the height of the mold. Pour in the custard, remove any foam, cover as hermetically as possible, and cook over a slow fire for about 1 hour. From time to time, remove lid to take off any foam that has formed. Serve unmolded and slightly chilled.