In a large bowl, or the bowl of a stand mixer, add the flour and yeast and combine. Add in the salt and combine again.
Make a well, pour in 3 tbsp Olive Oil and about 350ml warm water (not hot). Combine to form a dough. It should come together but be pretty sticky. If not, add more water.
Knead using the dough hook attachment or your hands on a lightly floured work surface for about 8 minutes (it should be soft, smooth but still a little sticky). Oil the bowl you used for the dough, place the dough back in it, cover with a tea towel and let rest for an hour - until doubled in size.
Lightly oil a 9x13" pan. Tip the dough in, stretch to the edges and let rest a further 30 minutes.
Preheat the oven to 220C/200C Fan/Gas 7. Prep your ingredients by slicing the brie into small chunks, the garlic into thin slices, and pull apart some sprigs of rosemary.
Press dimples into the dough using your fingertips. Combine 2 tbsp water with the remaining 3 tbsp olive oil and brush this over the bread. Top with the cheese, garlic and rosemary - placing at random.
Bake 20-25 minutes until golden. Let cool before slicing (Although, it is beautiful eaten whilst still warm).