filling: 3 cups chopped frozen or fresh rhubarb 1 cup sugar 3 Tbsp all-purpose flour Dash salt 3 large egg yolks 1-cup heavy whipping cream
Directions Cut shortening into flour, salt, and sugar in a small bowl until crumbly. Sprinkle egg and vinegar over crumb mixture. Stir in water with a fork until a ball forms. Chill covered for 1 hour until easy to handle.
Place rhubarb in crust. Whisk sugar, flour, salt, egg yolks, and cream; pour over rhubarb. Bake 50-60 minutes at 350° until filling sets and pie jiggles when gently shook.
Meanwhile, mix 4 teaspoons sugar and cornstarch in a small pot. Stir in water gradually. Stir continually while it boils until thickened, 1-2 minutes. Cool to room temperature.
In a small bowl, whisk egg whites and cream of tartar. Add cornstarch mixture and beat on high until soft peaksform. Mix in remaining sugar, 1 tablespoon at a time, on high until stiff glossy peaks form and sugar dissolves.
Cover hot filling and seal edges to crust. Bake meringue 15 minutes till golden brown. Cool on wire rack for 1 hour. Refrigerate.