Brown the crust: Using a fork, poke holes in the sides and bottom of the crust. Bake at 425 for 20 min. or until evenly browned. Remove and cool. Turn oven down to 350. Make cornstarch paste: Mix 1 tablespoon cornstarch and 1 tablespoon sugar in a small saucepan, then add 1/3 cup water and bring to a boil over medium heat. Using a wire whisk stir briskly and boil for 15 seconds. Remove the thick paste from heat, cover and set aside. Make lemon filling: 1. Zest and juice lemon. 2. Combine 1 1/2 cups sugar, 6 tablespoons cornstarch, and 1/4 teaspoon salt in a saucepan. 3. Gradually blend in until smooth: 1/2 cup cold water and fresh squeezed lemon juice. 4. Add egg yolks and blend thoroughly, then fold in butter, stirring constantly. 5. Stirring gently, slowly add 1 1/2 cups boiling water. Bring to a boil and allow to thicken slightly, reducing heat to very low and simmering for 1 min. 6. Fold in lemon zest. Remove from heat and set aside. Make the meringue: 1. In a clean mixing bowl, add the room temperature egg whites and beat with an electric mixer until foamy. 2. Add the vanilla and cream of tartar and beat until soft peaks form. 3. Slowly and gradually add the sugar and beat in well on high speed until very stiff and glossy but not dry. 4. Reduce the mixer speed to very slow and add the cornstarch paste 1 tablespoon at a time. When the paste is incorporated increase the mixer speed to medium-high and beat for another 10-15 seconds. Complete: 1. Pour lemon filling into baked pie crust. 2. Spread the meringue onto the outside edges then work toward the center with the remaining meringue. Use a rubber spatula to create peaks. 3. Bake for 20 minutes at 350 or until meringue peaks are golden brown. 4. Cool completely on a rack and serve, or refrigerate for up to 3 days.
Meringue isn't hard but it's definitely an art. Make sure to read all directions before you start and prep carefully. Keeping steps in this order ensures that your pie filling is still piping hot in the crust when you top it with the meringue, which prevents weeping.