Step 1

Thaw spinach, drain well. Squeeze excess liquid from spinach. Chop spinach and prosciutto coarsely.

Step 2

Preheat oven to 200°C (180°C fan forced). Oil deep 22cm (9-inch) square cake pan, line base and sides with baking paper, extending paper 5cm (2 inches) over sides.

Step 3

Line base of pan with one pastry sheet, trimming to fit, spread with mustard. Top with prosciutto and spinach. Crack 11 of the eggs, one at a time, into a cup, then carefully slide on top of spinach mixture, season. Top pie with remaining pastry sheet, trimming to fit. Brush pastry with lightly beaten remaining egg.

Step 4

Bake pie, uncovered, about 40 minutes or until browned lightly. Stand in pan 10 minutes before serving.