Carefully slice the top off each tomato to create a lid. Set to one side.
Gently loosen the flesh inside the tomato with a sharp knife then scoop out the seeds and pulp. Finely chop the tomato flesh and set aside with the tomato juices.
Preheat the oven to 180 degrees Celsius, 160 for fan assisted.
Heat the olive oil in a frying pan over a low/medium heat.
Add the onion and sweat until tender. Add the garlic, cooking gently until fragrant.
Add the lamb, stir well and cook until browned all over.
Add the dried herbs, spices, tomato purée and reserved tomato flesh and juices. Stir well to combine.
Add the stock and simmer until reduced right down.
Divide the lamb mixture between the hollowed tomatoes, pressing in firmly.
Scatter the feta over the lamb and replace the tomato lids.
Arrange the tomatoes on a shallow oven tray and drizzle with the remaining oil. Transfer to the oven to bake for 20 minutes or until cooked through and the tomatoes are tender.
Scatter with fresh coriander and pine nuts to serve.