Preheat the oven to 200 °C (180 °C fan). Wash the eggplants, cut them in half lengthwise, and score the flesh in a tight criss-cross pattern with a knife, taking care not to pierce the skin. Drizzle the halves with 15 ml of extra virgin olive oil, season lightly with salt and pepper, and place them cut-side up on a baking tray lined with baking paper.

Bake the eggplants for 25-30 minutes until the flesh is completely tender. Remove from the oven, let them cool for a few minutes, and gently scoop out the flesh into a bowl using a spoon, leaving an edge of about half a centimetre of flesh and the skin intact to form boats.

Heat the remaining 15 ml of extra virgin olive oil in a pan. Add the finely chopped onion and crushed garlic, then sauté until translucent for 3-4 minutes. Stir in the finely chopped scooped eggplant flesh, chopped canned tomatoes, drained canned tuna, and dried oregano. Season with salt and pepper, then simmer over medium heat for 6-8 minutes until the sauce thickens nicely.