Preheat oven to 200C (400F). Press spinach to remove excess moisture. Combine eggs, cheeses, spinach, onion, parsley, salt, pepper and nutmeg. Mix thoroughly. Lightly spray a 9 x 5 inch (23 x 13 cm) loaf pan with cooking spray. On a lightly floured surface, roll out two-thirds of pastry into a 16 x 11 inch (40 x 27 cm) rectangle. Ease pastry into pan. Brush with 2 tsp (10 mL) mustard. Layer ingredients in pan, as follows: half of ham, half of cheese mixture, sliced eggs, remaining ham, and remaining cheese mixture. Brush top of cheese mixture with remaining 2 tsp (10 mL) mustard. Trim pastry even with pan; brush edge with beaten egg. Roll out remaining pastry into a 11 x7 inch (27 x 17 cm) rectangle. Place over loaf. Trim excess dough to 1/2 inch (1 cm) all around. Fold excess dough under bottom crust and seal. Brush top with beaten egg. Make slits on top with a sharp knife. Bake pie in lower third of over 50 to 60 minutes, or until pastry is golden brown. Remove from oven and cool 30 minutes on wire rack. Loosen sides with a spatula and turn out on rack. Turn right-side up and serve.