Chop the chicken into small cubes. Slice mushrooms and chop the onion. Mince the garlic. This ensures quick and even cooking later.

In a frying pan, melt half the butter over medium heat. Add chicken and cook until lightly golden. Remove and set aside.

In the same pan, add remaining butter. Sauté onions and garlic for 2–3 minutes until soft and fragrant.

Add sliced mushrooms to the onions. Cook for 5–7 minutes until mushrooms release moisture and turn golden.

Sprinkle flour over the vegetables. Stir for 1–2 minutes to cook the flour. Gradually pour in chicken stock while stirring to avoid lumps.

Stir in double cream, thyme, salt and black pepper. Let the sauce simmer gently until thickened.

Return cooked chicken to the pan. Stir well to coat the chicken in creamy sauce. Remove from heat and let cool slightly.

Roll out the shortcrust pastry to fit your pie dish. Place a portion of pastry in the base and sides of the dish. Trim excess edges.

Spoon the chicken and mushroom mixture into the pastry-lined dish. Spread evenly.

Place remaining pastry over the filling. Press edges to seal. Cut a small slit in the center for steam to escape. Brush the top with beaten egg for a golden finish.

Preheat oven to 200°C / 400°F. Bake the pie for 25–30 minutes until the pastry is golden and crisp.

Let the pie cool for 5 minutes before serving. Slice and enjoy the creamy filling with the flaky pastry.