Preheat the oven to 400 degrees.

Heat a large shallow pot over medium heat. Add in the olive oil and then add in the onions, salt, and sugar and stir/cook on medium heat for 30 minutes until deeply brown caramelized.

Add in the carrots, fresh thyme, and garlic and cook for about 1 minute until fragrant.

Deglaze the pot with the dry white wine and continue to cook until the liquid reduces by half.

Sprinkle in the flour in and continue to cook for about 1 minute to create a roux.

Then slowly pour in the beef broth, stirring constantly to avoid lumps. Continue to cook until the sauce thickens and coats the back of a spoon.

Then add in the whole milk and Worcestershire sauce and simmer the sauce until it thickens again.

Turn off the heat and stir in 1 cup of gruyere cheese and stir until the cheese has melted. Then add in the shredded cooked chicken and frozen peas. Season generously with salt and pepper to taste.

Sprinkle the remaining gruyere cheese on top of the pot pie.

On a lightly floured surface, gently roll out the puff pastry and cut into 2 inch equal squares. Arrange the puff pastry squares on top of the pie.

Brush the top with some egg wash and then place the entire pot on top of a baking sheet in case anything drips. Bake for about 30 minutes, or until the puff pastry is golden brown and crisp on top.

Garnish with fresh thyme and parsley and serve while it’s still hot!