How to bake olive/spinach/cheese etc. pastes on top of bread?

I had bread from a store whereby the spinach+cheese filling is baked as part of the bread. The bread is in the shape of a rowing boat, and it's like the sides have been pulled thinly over the filling.

To make this type of bread, should I prepare a bread roll, make the slice at the very last step and then stuff the filling inside? Or should it be like a flat yeasted bread, topped with filling and then letting the yeast work at room temperature to bulk it up before putting it in the oven?