Step 1: Prepare the Brisket Filling

1. Heat olive oil in a Dutch oven over medium heat.
2. Season brisket with salt and black pepper.
3. Sear the brisket pieces until browned on all sides, then remove from the pot.

Step 2: Cook the Vegetables

1. In the same pot, add onions, carrots, and celery.
2. Sauté until the vegetables soften (about 5 minutes).
3. Add garlic and cook for another 1 minute.

Step 3: Build the Sauce

1. Stir in tomato paste and cook for 1 minute.
2. Sprinkle flour over the vegetables and stir well.
3. Pour in beef broth, wine (if using), Worcestershire sauce, thyme, rosemary, and bay leaf.
4. Bring to a simmer, then return the brisket to the pot.
5. Step 4: Slow Cook the Brisket
6. Cover and cook on low heat for 2 ½ – 3 hours until the brisket is tender.
7. Remove the bay leaf and adjust seasoning if needed.

Step 5: Prepare the Pie Crust

1. In a mixing bowl, combine flour and salt.
2. Add butter and mix until the texture resembles coarse crumbs.
3. Gradually add ice water, mixing until the dough comes together.
4. Divide into two portions, wrap in plastic, and refrigerate for 30 minutes.

Step 6: Assemble the Pot Pie

1. Preheat oven to 375°F (190°C).
2. Roll out one portion of dough and fit it into a pie pan.
3. Pour the brisket filling into the pie crust.
4. Roll out the second portion and place it over the filling.
5. Seal the edges, cut slits in the top for ventilation, and brush with egg wash.

Step 7: Bake the Pot Pie

1. Place the pie in the preheated oven.
2. Bake for 35-40 minutes until the crust is golden brown.
3. Let it rest for 10 minutes before serving.