Technique
In a DRY blender process the meringue sugar (1 cup plus 2 tablespoons) until finely powdered. Set the powdered sugar aside in a small bowl. This will be used for preparing the meringue and is not added to the pie filling mixture.
Preheat the oven to 375°F. Bake the pie crust for 12 to 15 minutes or until lightly browned around the edges. Remove and set aside to cool.
In the same blender, process the pie filling ingredients until smooth. Pour the blender contents into a large saucepan and cook over medium heat, stirring frequently with a flexible spatula. The mixture will be foamy and milky in appearance. Stir constantly as the mixture begins to thicken. Keep stirring until the mixture begins to bubble and the milky and foamy appearance transforms into a thick and gelatinous lemon curd.
Pour the filling into the pie crust, smooth the top gently with a rubber/silicone spatula or the back of a spoon and place in the refrigerator uncovered for a minimum of 2 hours until the top of the pie is firmly set.
After the pie has chilled for a minimum of 2 hours, preheat the oven to 200°F while preparing the meringue.
Preparing the Meringue
Strain the liquid from the can of beans into a large mixing bowl or the bowl of a stand mixer. Sprinkle in the food gum and begin whipping on high speed for 3 minutes.
Gradually begin to incorporate the powdered sugar, in increments, while whipping. Continue to whip the mixture until soft peaks begin to form. Add the vanilla and continue to whip the mixture until it is voluminous and stiff peaks begin to form.
Spoon and spread the meringue onto the surface of the pie, avoiding the edges by ½-inch. Create soft peaks in the meringue using the back of a spoon. Bake in the oven for 30 minutes. To lightly brown the meringue, set the oven on Broil and position the pie on an oven rack close to the flame source. Keep the oven door open while doing this and watch the meringue carefully it will brown quickly and can burn easily. Rotate the pie as needed until the peaks are evenly browned.
Remove to cool for about 5 minutes and then place the pie in the refrigerator to chill thoroughly for several hours until completely set before serving. Keep the pie refrigerated but do not cover or the meringue will turn into a gooey liquid.
For Mini Lemon Meringue Tarts
Prepare the pie filling according to the recipe. Fill individual frozen mini fillo cups with the filling and refrigerate as recommended. Then top with a small dollop of meringue and bake according to the directions. Refrigerate until chilled and serve.