Ingredients
1 1/2 cups sugar
3 tablespoons cornstarch
Salt
2 cups warm water
1 stick unsalted butter, cut into small pieces
1 tablespoon finely grated lemon zest plus 1/2 cup fresh lemon juice (from 2 lemons)
1/4 cup blood-orange and lime juice (mixed, or one or the other)
Preparation
Combine sugar, cornstarch, and 1/4 teaspoon salt in a medium saucepan. Whisk in water. Bring to a boil, whisking. Continue to boil, whisking, until clear and thick, about 6 minutes more.
Stir in butter, lemon zest, and citrus juices. Cook, stirring regularly, until smooth, 2 to 3 minutes more.