Prepare the bread mix to pack instructions, then shape the dough into a 22cm x 30cm rectangle. Place on a greased baking tray, cover with a clean tea towel and leave to rest until doubled in size - this will take about 1 hour.
Preheat the oven to 200°C, fan 180°C, gas 6. Once the bread has risen, push deep holes into the dough using an oiled finger. Scatter the onion and parsley over the top then season with salt and freshly ground black pepper. Drizzle with the olive oil, making sure some pools in the holes.
Bake for 20 minutes until the bread springs back when touched.