In a large heavy saucepan over medium-high heat, cook the bacon until it is crisp and has released almost all of its fat, about 6 minutes. This is called rendering. Add the pork, Essence, salt, pepper, cinnamon, and cloves and cook, stirring to break up any lumps, until the meat is well browned, about 6 minutes. Add the onion and celery and cook until vegetables are soft, about 4 minutes. Add the garlic and cook for 1 minute. Add the savory and flour and cook, stirring, for 2 minutes.
Add the chicken broth, water, and bay leaf and cook, stirring occasionally, for about 30 minutes, until almost all of the liquid has evaporated and the meat is tender and flavorful. Stir in the parsley. Taste and adjust the seasoning, if necessary. Remove the bay leaf, which is bitter and non-edible. Set the filling aside to cool to room temperature, then transfer to a medium mixing bowl and refrigerate, covered, until thoroughly chilled, about 2 hours or up to overnight.
Prepare the piecrust according to the recipe on page 119. On a lightly floured surface, use a rolling pin to roll out one disk of the dough to a thickness of 1/8 inch. Gently fold the pastry circle in half, then in half again so that you can lift it without tearing it. Then unfold it into a 9- or 91/2- by 2-inch deep-dish pie pan. Trim the edges so that they are even and extend about 1/2 inch beyond the edge of the pie pan.
Spoon the chilled meat mixture into the piecrust. Lightly brush the edges of the pastry with some of the beaten egg yolk.
Again on a lightly floured work surface, roll out the remaining pastry disk to a thickness of 1/8 inch. Fold the pastry as before, then transfer it to the top of the pie and gently unfold it. Trim the edges so that they match up with the bottom crust and press to seal.
Using your fingers, carefully tuck any excess pastry into the side of the pie pan and, using your fingers or a fork, press or crimp the pastry in regular intervals to form a decorative edge. Using a sharp paring knife, cut several small steam vents in the top of the pastry so that steam may escape while the pie is cooking. Refrigerate the pie for at least 15 minutes before baking.
Position rack on lowest rung of oven and preheat the oven to 425?F.
Using a pastry brush, lightly brush the top of the pie with some of the remaining beaten egg yolk mixture. Bake the pie for 20 minutes, then reduce the heat to 350?F, and continue to bake the pie until the crust is golden brown, another 35 to 40 minutes.
Yield: one 9 1/2-inch deep dish pie