Preheat the oven to 200°C/390°F. Heat the olive oil in a frying pan over a medium heat. Add the onions and cook until softened. Add the garlic, cherry tomatoes, tinned tomatoes and salt and pepper to taste. Cook for 10 minutes.
In a large baking dish arrange a layer of aubergine slices and top with a layer of tomato sauce. Repeat this process until you've used all of the ingredients, finishing with a layer of tomato sauce.
Place in the oven and cook for 40-45 minutes. Serve topped with chopped parsley, crumbled feta and alongside a grain of your choice.