First toast the 2 slices of bread in the toaster or pan don't over toast, just toast a bit is easier at the time of cutting each slice
Cut each bread slice in half
How it looks when cut
Add butter to the bread slices
Add the cheese
Add the other slice of bread and repeat the process.
Add cheese, tomato, onion and oregano.
Add 1 slice of cheese
Add the other half on top
Ready to cut.
Finished product, at the end you will have four layers.