In a large bowl, combine the cubed beef with flour, salt, black pepper, garlic powder, and onion powder. Toss until the beef is evenly coated.

Heat the olive oil in a large skillet over medium heat. Add the coated beef and cook until browned on all sides. Remove the beef from the skillet and set it aside.

In the same skillet, add the diced onion, carrots, celery, and minced garlic. Cook until the vegetables are softened, about 5 minutes.

Return the beef to the skillet and add the beef broth, grape juice, tomato paste, thyme, and rosemary. Stir well to combine. Bring the mixture to a simmer, then reduce the heat to low and let it cook for about 30 minutes, or until the beef is tender.

Stir in the frozen peas and corn, and cook for an additional 5 minutes. Remove the skillet from the heat and let the filling cool slightly.

Preheat your oven to 375°F (190°C).

Transfer the beef filling to a 9-inch pie dish. Roll out the puff pastry sheet and place it over the top of the pie dish. Trim any excess pastry and crimp the edges to seal.

Brush the top of the pastry with the beaten egg to give it a golden finish.

Place the pie dish in the preheated oven and bake for 25-30 minutes, or until the crust is golden brown and flaky.

Remove the pie from the oven and let it cool for a few minutes before serving.