Heat the oven to 200°C/Fan 180°C/Gas 6. Trim the aubergines. Slice in half lengthways. Use a knife to slice diagonal lines across the cut surface of each aubergine half. Put in an ovenproof dish, cut side up.
Season with salt and pepper. Drizzle with olive oil. Bake for 20 mins till the flesh is soft. Put to one side to cool a little. While the aubergine cooks, peel and chop the onion. Peel and grate or crush the garlic.
Warm a drizzle of oil in a frying pan. Add the lamb. Fry over medium heat for 5 mins. Stir every so often till browned. Drain off any excess fat. Add the garlic and onion. Fry for 5 mins till glossy. Roughly chop the oregano leaves.
Measure out 1 tsp of the cinnamon. Add it to the mince. Cook and stir for 30 secs. Add the chopped tomatoes. Half fill the can with water. Add that to the pan. Stir in the oregano. Season.
Pop a lid on the pan. Bring to the boil. Turn the heat down. Simmer for about 10 mins till the sauce is thick. Once the aubergines have cooled slightly, use a spoon to scoop out the flesh. Leave the skins intact.
Roughly chop the aubergine flesh. Add to the mince. Taste and adjust the seasoning. Spoon into the aubergine shells. Crumble half a pack of feta over the top of the aubergines.
Bake the aubergines for 20 mins till the cheese is golden. While they cook, wash and dry the salad leaves. Whisk 2 tbsp of the vinegar with 2 tbsp olive oil and some salt and pepper.
Drizzle the dressing over the leaves. Toss to mix. Serve with the stuffed aubergines.