Note: Adapted from Dolly Chammaa of Sunnin Lebanese Cafe in Westwood and Long Beach. Mastic, the crystallized resin from the mastic tree, can be found at C&K Importing Co. in Los Angeles and Super Hayat Market in Torrance, and at Middle Eastern and Greek markets. She recommends serving ashta with baklava, or on its own topped with bananas, honey or pistachios.
1 quart half-and-half
2 slices white bread (crusts removed), cut into small dice
1/4 teaspoon mashed mastic
2 tablespoons powdered sugar
1/4 cup plus 1 tablespoon cornstarch
1/2 cup rose water
1/2 cup orange blossom water
1. Place the half-and-half, bread and mastic in a large nonreactive pot over medium-low heat and allow it to come gently to a boil, about 1 hour, stirring occasionally.
2. While the half-and-half mixture is coming to a boil, combine the powdered sugar, cornstarch, rose water and orange blossom water in a small saucepan. Heat the contents over low heat, stirring constantly, until the sugar is melted, about 1 minute.
3. When the half-and-half mixture comes to a boil, increase the heat to high and add the sugar mixture, stirring constantly until it thickens like a custard. Remove from the heat.
4. Spread the contents onto a large (approximately 15-inch-by-10-inch), rimmed sheet pan and allow to cool. Skim the thickened layers into a medium bowl as they form on the surface of the cream; you will have 2 to 3 layers. Place the custard in a separate medium bowl, then cover both bowls and refrigerate until cold.
5. When cold, mix together the skimmed layers and custard. Cover and refrigerate until needed. Serve cold.