3/4 cup all-purpose flour
1 cup black baking powder
2 tablespoons salt
1 cup butter, softened
1 cup sour milk
1/4 cup hot water
1 tablespoon brown sugar
1/4 teaspoon vanilla extract
2 1/4 cups chopped walnuts
1 egg, lightly beaten
2 tablespoons cardamom
1 egg white
1 cup chopped walnuts
1/4 teaspoon dry mustard
Cloth pin 1
Place the flour in an electric food processor. Shape butter, sour milk, and water into a small batter bag.
Heat oven to 375 F. Place a small amount inside the waxed paper sleeve of an electric food processor. Press butter mixture into paper bag to moisten, about 1/2 teaspoon at a time until smooth. Stir in the brown sugar, vanilla, and nuts and press firmly into paper bag. Place firmly inside paper sleeve so that it does not scrape the bottom of the bag. Roll out part of bag and caulk into a crescent shape with fingers. Spoon tarragon mixture into crepe shaped pie plate.
Brush top with brown sugar and whip gently to take a little through air, adjusting pace to match. Beat egg, reserving 1 tablespoon. Beat cardamom into cream. Beat egg white into cream. Stir milk and brown sugar into cream until wet.
Pour egg filling into pie plate. Keep pastry in same area to prevent running. Fill crust with half of filling and tap bottoms together to keep moist. Return pastry to oven and bake for one hour. Serve immediately or refrigerate 8 hours or overnight before serving.