1. ROAST CHICKEN: Wash chicken, remove excess fat, season cavity, place onion and bay leaf in the cavity of the chicken with carrot, celery and parsley. Truss chicken, season outer surface, sprinkle with garlic and place in a roasting pan.
2. Roast in preheated 180 ºC oven for 1 1/2 hours, basting during roasting.
3. PIE FILLING: Fry onion until soft, add garlic and fry for a further 3 minutes. Add flour, cook while stirring over medium heat for 1 minute. Stir in milk and bring to the boil, stirring constantly until sauce thickens. Add seasonings and cool. Stir in chicken, cheese, eggs, and chopped parsley.
4. Lightly grease a 23 cm springform cake tin.
5. Place pastry on work surface. Cover with a damp cloth. Take two sheets from under the cloth, brush each with melted butter and layer together. Fold layered sheets in half and place in prepared tin with pastry edges overhanging. Repeat process three more times, overlapping strips and working around the tin in a clockwise direction until it is completely covered with pastry.
6. Spoon prepared filling into pastry shell, fold overhanging edges back over the filling, brush with melted butter.
7. Brush remaining sheets with butter, fold in half and place on top of pie. Trim and brush with butter.
Bake in preheated 180 ºC oven for 35 to 40 minutes. Cover with foil if pastry becomes too brown during baking time.