For the pie crust, let the frozen butter thaw at room temperature for about 10-15 minutes, or until it begins to soften just slightly. (Alternatively, you can place chilled butter in the freezer for 15-20 minutes or until almost frozen. I just always have sticks of butter in the freezer.)
Sift together the flour, salt, and sugar in a large bowl. Using a box grater, grate the butter into the flour (using the largest holes), or cut it into small cubes. Cut the butter into the flour or just use your fingers until the butter forms pea-sized clumps in the dough.
Add the water, making sure it’s very cold, and stir with a spoon until the dough comes together. Give it a little time (and use your hands to press the dough together if need be), but if it remains too dry, add a teaspoon or two more water. Form into a ball, wrap in plastic wrap and chill in the refrigerator for at least an hour and ideally overnight. You can also freeze it for later use.
Next, you’ll need to roll out and prebake the crust. Divide the ball into two equal pieces, and roll back into a round ball. Starting with a round ball of dough makes it infinitely easier to roll it into a good circle. Lightly flour two pieces of parchment paper, and place one ball in between the two pieces, returning the other to the fridge to chill. Gently roll out the dough, using the rolling pin in one direction (outward) only, and rotating the dough with every roll to ensure it’s rolled out evenly. Ease up the pressure as you roll outwards so that the crust won’t be too thin on the edges. When you turn the pie pan upside over the crust and the crust extends at least 1/2-inch on all sides, it’s large enough. Press the crust gently into the pan, and crimp and prepare the edges as you prefer. Cover with plastic wrap and place in the freezer as you prepare the other crust, then let the other crust freeze as well.
Meanwhile, preheat the oven to 425 degrees F. When the crusts are frozen and hard to the touch, remove from the freezer and line tightly with foil, covering the edges of the crust. Place pie weights (read: for me, regular old pennies and nickels) in the bottom, taking care to line evenly. Bake on the bottom rack of the oven for 10-15 minutes, or until edges of the pie are set but not browned. Lift out the pie weights (the center of the crust will still look underbaked) and let the crusts cool while you prepare the filling.
Preheat your oven (or adjust your oven) to 325 degrees F. In the smallest sauce pot you have, combine the heavy cream, chamomile, and thyme over low heat. Heat the cream for 4-5 minutes, stirring continuously, until cream is warm and heavily flavored with the tea and herbs. (It will be quite diluted in the custard.) If the cream begins to bubble, remove immediately from heat and simply let it steep for a few minutes off the heat. Pour the cream through a fine mesh strainer to strain out the chamomile and herbs, and place in fridge to cool.
In a medium bowl, whisk together the sugar, cornmeal, flour, and salt. Add the melted butter and stir until incorporated (the consistency will be like wet sand).
Beat the egg lightly, then add it to the mixture and whisk briskly until the filling is thick and light-colored, about 2-3 minutes. Stir in the heavy cream and whisk again briefly until incorporated.
Finally, divide the filling evenly between the two shells. Bake on the middle rack of the oven for about 25-30 minutes, or until the tops are golden brown, the edges are set, and the center jiggles very slightly but is not liquid. If the tops are browning too quickly, cover with foil for the last 10 minutes of baking.