Heat oil in a fry pan over medium heat.
Fry the bread for 2-3 minutes, brushing oil on the exposed side. Flip, then fry the other side for 2-3 minutes.
Remove from pan, and carefully run the knife around the edge, slowly working your way towards the centre until you end up with two halves.
Sandwich the filling between the two rounds of bread.
Return to the frying pan and cook for another 2 minutes on each side.
Remove from the pan, cut into wedges and serve straight away.