Preheat oven to 200°C or 180°C fan. Grease a 12-hole, 1/3 cup-capacity muffin pan.
Cut 12 x 8cm squares from pastry. Ease pastry squares into prepared pan, allowing corners of pastry to overhang.
Using hands, squeeze excess liquid from zucchini. Place in bowl with 4 eggs, milk and parmesan, whisk to combine. Season. Divide egg mixture between pastry cases and top with tomato. Lightly beat remaining egg and use to brush pastry edges.
Bake for 20 mins, until pastry is golden and filling is set. Cool in pan for 5 mins, then transfer to a wire rack to cool. Serve warm or at room temperature.