LEMON MERINGUE ICE CREAM

Steps:

• Make meringue:
• Preheat oven to 250° F. and line a baking sheet with parchment paper.
• In a bowl with an electric mixer beat whites with salt until they hold soft peaks. Gradually beat in sugar and beat until meringue holds stiff, glossy peaks. Spread meringue 1/2 inch thick on parchment-lined baking sheet and bake in middle of oven 1 hour, or until firm to the touch. Turn off oven and let meringue stand 1 hour. Transfer meringue on parchment to a rack and cool. Peel off parchment and, working over a bowl, break meringue into 1/2- to 1-inch pieces. Meringue may be made 3 days ahead and kept in an airtight container in a cool, dry place.
• In a heavy saucepan bring cream, milk, sugar, zest, and salt just to a boil, stirring occasionally. In a bowl beat yolks until smooth. Add hot cream mixture to yolks in a slow stream, whisking, and pour into pan. Cook custard over moderately low heat, stirring constantly, until a thermometer registers 170° F. Pour custard through a sieve into a clean bowl and stir in lemon juice. Cool custard. Chill custard, its surface covered with plastic wrap, at least 3 hours, or until cold, and up to 1 day.
• Freeze custard in an ice-cream maker. Transfer ice cream to a bowl and fold in meringue. Transfer ice cream to an airtight container and put in freezer to harden. Ice cream may be made 1 week ahead.