If using a ready-made crust, proceed to step 5, rolling out crust with a dusting of corn meal and blind baking.
To make all-butter crust, cut the butter into small pieces and chill in the freezer for 10 minutes. In the bowl of a food processor fitted with the blade attachment, pulse together the flour, salt, sugar and butter until the mixture resembles cornmeal with some pea-size pieces of butter remaining.
In a small bowl, stir together the ice water and the lemon juice. Slowly add the liquid to the flour mixture, pulsing, until the dough just comes together. Squeeze a small piece of dough between your thumb and index finger to make sure it holds its shape.
Turn the dough out onto a lightly floured surface. Gently fold the dough a few times so that any dry bits are incorporated. Form into a loose disk, wrap in plastic and refrigerate for at least 20 minutes. If using a ready-made crust, skip to the next step.
Dust a work surface with corn meal and roll out crust and fit it into a 9-inch pie pan. Dock the dough ( prick all over the surface with the tines of a fork) and refrigerate it for 30 minutes. Preheat the oven to 350 degrees F.
Crumple a 9" square of parchment and then spread it flat. Line the crust with the parchment, fill it with pie weights or dried beans and bake it for 15 minutes. Remove the pie weights and the parchment and bake the crust for 5 to 10 minutes more, just until the raw-dough sheen goes away. Set the crust aside.
For the filling: Bring the chicken broth, Cajun spice, cayenne and butter to a boil in a large saucepan. Stir in the grits and whisk until combined. Reduce the heat to low and simmer until the grits thicken, 8 to 10 minutes.
Meanwhile, peel the potato and dice into 1/2 inch cubes. Place it in a small saucepan filled with water and boil until it is just barely fork-tender, 6 – 8 minutes.Cool slightly.To the cooked grits,add the potatoes, the Cheddar, bell pepper, jalapeno, corn, and andouille, stirring gently to combine well. Test the seasoning and add salt to taste.
In a small bowl, whisk the eggs together with the heavy cream and stir the mixture into the grits. Lay the shrimp on the pie crust, distributing evenly.Pour the grit and egg mixture into the crust over the shrimp. Smooth the top and bake the pie at 350º Ffor 35 to 40 minutes, or until the custard is set. Cool slightly before cutting into wedges.