Pre-heat oven to 180C/350F.
Roll your puff pastry onto a lined baking tray (with baking paper).
Cut into rectangle shapes - I did 8 but you could do smaller ones if you wish.
Then score a rectangle within each tartlet, leaving 1-2 cm edge (be careful not to let the knife cut through to the bottom).
Brush an egg wash onto the edges.
Add a tsp caramelised onion into the centre of each pastry followed by two thick cubes of brie.
Bake for 17-19 minutes, or until the pastry is golden.
Finish with some chopped rosemary and enjoy!!
