Cut the aubergines in half lengthways. Score the cut surfaces lightly, with a sharp knife, making sure that you do not break the skin. Brush lightly with 1 tsp of the oil and sprinkle with salt.

Place the aubergines on a lightly greased baking sheet and cook in a preheated oven, 190°C/375°F/ Gas Mark 5, for 15 minutes. Allow to cool slightly

Scoop the flesh carefully from each half aubergine, leaving about 0.5cm (1/4 inch) around the edge, to form a shell. Chop the flesh.

Fry the onion in the remaining 2 tbsps of the olive oil. Add the garlic and the chopped aubergine flesh. Cook for 2 minutes, then stir in the rice, mayonnaise, tuna, tomatoes, parsley and seasonings. Mix together thoroughly

Divide the rice mixture equally between the aubergine shells. Place the filled aubergines in an ovenproof dish and bake for 25 minutes.