Heat oven to 220C/200C fan/gas 7.
Heat the butter in a frying pan until
sizzling, then add the bacon and cook for
6 mins until just starting to crisp. Add the
onions and sweat for 10 mins until soft,
sticky and golden. Pour in the cream,
take off the heat and leave to cool a little.
Meanwhile, roll the pastry out on a
lightly floured surface to a rectangle a little
larger than this magazine and transfer to
a baking tray. Roll the edges up and press
down to create a raised border.
Tip the creamy onions into a bowl. Mix
in the grated cheese and most of the
beaten egg. Spread the mixture over the
pastry, then scatter over the tomatoes
and crumbled cheese. Brush the borders
with the remaining beaten egg, then
bake for 20 mins until golden. Leave to
cool, then cut into squares. Enjoy warm
with salad or cold on a picnic.