Preheat oven to 375 degrees F.
Roll out the pie crust on a lightly floured surface to fit a deep 9 or 10-inch pie pan. Place the pastry in the pie pan and crimp edges decoratively. Refrigerate at least 30 minutes, then line with aluminum foil. Fill with pie weights and bake for 12 to 15 minutes, or until lightly golden around the edges. Remove foil and pie weights, and return to the oven for 3 to 5 minutes. Remove from the oven and transfer to a cooling rack to cool. Crack the egg in a small bowl, reserving yolk for the filling, separately. Lightly beat the egg white with a fork, then brush the surface of pie crust with a light coating of egg white and allow to cool.
Slice the tomatoes, discarding the stem and root ends, into 1/4-inch slices and lightly season with the salt and pepper.
Sprinkle about 1/3 of the bread crumbs in the bottom of the pie crust. In a small bowl combine the mayonnaise with the reserved egg yolk and stir until smooth. Place a layer of tomatoes in the bottom of the piecrust over the breadcrumbs, using about half of the tomatoes, then top with half of the sliced onions. Drizzle with half of the mayonnaise mixture, half of the thyme and basil, half of the fontina and half of the mozzarella cheeses. Top with half of the remaining breadcrumbs then top with the remaining tomato slices, remaining onions, remaining fontina and mozzarella, remaining mayonnaise mixture, and remaining thyme and basil. Top with the remaining bread crumbs and drizzle with the olive oil. cover with the Parmesan cheese, place in the oven and bake until bubbly hot and golden brown, about 1 hour and 15 minutes. Remove from the oven and allow to cool for at least 30 minutes before slicing and serving. Serve warm or at room temperature.
2 teaspoons Essence, recipe follows
In the bowl of a food processor combine flour, Essence, salt, and butter and process until mixture resembles coarse crumbs. While the motor is running, add water in increments until dough comes together to form a ball. Transfer dough to a lightly floured surface and shape into a flat disc. Refrigerate overnight or at least one hour.
Remove from refrigerator and roll out on a lightly floured surface to desired shape and thickness.
Combine all ingredients thoroughly.
Recipe from "New New Orleans Cooking", by Emeril Lagasse and Jessie Tirsch, Published by William Morrow, 1993.