Slice up the sourdough into 1cm thick pieces. Take a cake tin and brush with oil all over. Layer the sliced sourdough to cover the bottom completely. Spread on half the tomato passata then top with half the cheddar, mozzarella, your chosen dried meat slices, parmesan and basil leaves.
Now lie another layer of sliced sourdough on top to completely cover the filling. Brush with oil, sprinkle with oregano and season.
Bake for 10 minutes until the top of the bread is golden brown.
Finally, top the golden bread layer with the remaining passata, cheese, basil and meat slices. Grill for 10 minutes until the cheese has melted. Serve up in slices!