Step 1

Melt the butter with the olive oil in a heavy pot. Sear the meat over medium-high heat in batches until brown, 4 to 5 minutes; remove to a plate.

Step 2

Add the carrots, celery and shallots and saute until the vegetables start to wilt, about 5 minutes. Reduce the heat to medium low, add the mustard, garlic and 1 tablespoon of the flour and saute for 1 minute. Add the mushrooms and cook for 2 minutes. Pour in the wine, beef broth and 1 cup water. Add salt and pepper to taste and stir. Bring to a boil. Return the browned meat to the pot and reduce the heat to low. Add the bay leaves and thyme sprigs, then cover and simmer for 30 to 45 minutes.

Step 3

After 45 minutes, mix the remaining 2 tablespoons flour with a little water and pour into the stew. Cook and thicken for 10 more minutes. Remove from the heat and set aside to cool completely.

Step 4

Preheat the oven to 425 degrees F.

Step 5

On a lightly floured work surface, roll out the puff pastry sheets one by one to get rid of the creases. Set a 6- to 8-inch ovensafe skillet upside down on a pastry sheet and cut a circle around it, making it 1/2 inch larger than the dish. Repeat with the remaining 5 skillets using all of the pastry sheets; discard the scraps.

Step 6

Put the 6 skillets onto 2 baking sheets and fill the skillets with the cooled beef mixture. Sprinkle over some chopped bacon and 1/2 teaspoon chopped parsley on each.

Step 7

Top each skillet with a pastry circle, pressing along the edges to seal. Mix together the egg and 1 tablespoon water in a small bowl to make an egg wash. Brush each pastry lid with the egg wash. Bake until the pastry is puffed and golden brown, 20 to 25 minutes.