1. Heat oven to 400 degree F. Roll out pie crust into a 12-inch circle and fit into a 9-1/2-inch deep-dish pie plate. Trim edges so pastry is even with rim of pie plate (do not turn under or crimp). Brush lightly with beaten egg and prick all over with a fork. Bake until golden, 8 to 10 minutes. Remove from oven and let cool on a wire rack.
2. In a large skillet or Dutch oven, cook bacon over medium heat until browned, about 3 to 5 minutes. Drain on paper towels, crumble, and set aside. Discard all but 1 tablespoon of the bacon fat from skillet. Add half the beef and cook over medium-high heat until well browned on all sides, about 5 minutes. Remove and repeat with remaining beef. Return all the beef to the pan, stir in flour, and cook 1 minute. Add mushrooms, broth, wine, oil, shallots, garlic, bay leaf, thyme, salt, and pepper. Bring to a boil. Reduce heat to low, cover and simmer, stirring occasionally, until beef is just tender, about 1 hour. Add carrots and leek. Cover and cook 35 to 45 minutes more. (Mixture should be the consistency of a stew, but not too saucy.) Remove bay leaf; stir in bacon and set aside.
3. On a lightly floured work surface, roll puff pastry to a 12-inch square. With a 1-inch-round cookie cutter or sharp knife, cut a 1-inch hole in the center. Pour filling into the baked pie crust. Brush puff pastry lightly with remaining beaten egg and fit over filling. Trim pastry edge to make a 1-inch overhang. Bake until pastry is puffed and golden, 20 to 30 minutes. Makes 8 servings.