In the food processor, combine the flour, sugar and salt. Add the cubed butter and pulse until crumbly.
In a small bowl whisk together the egg yolks and water, gradually add through food chute. Pulse until mixture comes together.
Form a disk and wrap with plastic wrap and chill for at least 1 hour.
Roll out to about 1/8 inch and form into tart pans, pressing up the sides. Prick bottom with fork, add a small piece of parchment paper and pie weights.
Bake at 350 degrees for about 20 - 25 minutes or until golden brown. Remove from oven and cool.
In a saucepan, combine flour, cornstarch and sugar. Gradually add water, whisking constantly.
Heat to boiling over medium heat, cook and stir for 1 minute, remove from heat.
Whisk egg yolks in a small bowl. Gradually add 1/2 cup of cooked mixture, whisking constantly.
Stir the egg mixture into the cooked mixture. Stir in butter, lemon juice and peel, cook over medium heat for about 5 minutes until thickened, stirring constantly.
Remove from heat and let stand 10 minutes. Pour into cooled tart shells and place in fridge for at least 2 hours.
Spoon pie filling on top. Add whip cream and more pie filling, if desired. Store leftovers in fridge in airtight container.