Finely chop the onion, tomato, and garlic. Remove the tomato stem before chopping.

Peel the eggplants in stripes and soak them in water for 10 minutes. Pat dry with paper towels.

Heat 1 tbsp olive oil in a pan and cook the eggplants on low heat, turning occasionally until soft and browned. Remove from the pan.

In the same pan, heat 1/2 tbsp olive oil and sauté garlic until fragrant. Add onion and cook until softened. Stir in tuna and tomato, cooking until well combined.

Add sugar, ketchup, medium-thick sauce, and salt and pepper. Cook until the mixture becomes a paste-like consistency.

Make a slit in each eggplant and fill with the prepared mixture. Repeat for all three eggplants.

Place the stuffed eggplants in a clean pan, add 100cc water, and bring to a boil. Cover and simmer on low heat for 15 minutes.