Preheat the oven to 200°C
Roll the pastry out on a floured surface and line a loose-bottomed 28cm diameter by 2.5cm deep tart tin.
Carefully fold the off-cuts so you don't upset the layers of pastry and keep these to the side.
Brush the mustard all over the inside of the pastry-lined tin. Pour in ¾ of the eggs.
Sprinkle the ham pieces evenly on top of the egg. Reserve the remaining egg. Sprinkle the cheese evenly on top.
Dot the tomatoes and olives over the filling.
Roll out the off-cuts and cut 10 strips 2cm wide, you will need to roll off-cuts again to make this number.
Place 5 strips evenly spaced over the tart. Put the other 5 on top, transecting the first lot. Gently press the ends into the base to secure them for baking. Brush the strips with the remaining egg. Place in the oven for 30-35 minutes or until well-browned and puffed up.
Remove from the oven and serve warm with extra mustard.
