Preheat the oven to 200°C, fan 180°C, gas 6. Unroll the pastry and cut into 6 pieces. Roll each one a little thinner with a rolling pin then use to line 6 x 10cm loose-based tart tins. Trim the excess pastry, prick the bases with a fork and chill for 20 minutes.
Bake the pastry cases blind for 10-12 minutes until pale golden. Meanwhile, steam the Tenderstem® for 3-4 minutes until just tender. Refresh under cold water and cut into short lengths.
Fill the pastry cases with the ham, tomatoes and Tenderstem®. Whisk the eggs and milk together in a jug and season to taste. Pour the milk mixture into the cases, taking care not to overfill.
Bake for 20-25 minutes until set and golden. If the Tenderstem® tips start to over-brown, cover loosely with foil. Serve warm or cold.