Roll dough into a square, approximately 10×10 inch square, set aside.
Sauté the red onion and garlic in the olive oil until soft and caramelised, season with salt and pepper and set aside.
Add spring onions into the used pan and sauté until glossy, set aside.
Spread the mustard and mayonnaise onto the pastry, leaving an inch gap around the edges. Pour the onion and garlic mixture on top evenly and top with the cheese.
Cutting from the edge of the dough to the start of the filling, make slits in the border of the dough every 2″, fold flaps over filling.
