Heat 3 tablespoons of olive oil in a wide pot over medium heat. Add the diced onion and sauté for 2–3 minutes, stirring occasionally, until slightly softened.

Add the sliced carrots and cook together for another 2–3 minutes.

Stir in the tomato paste and cook for about 1 minute, mixing well.

Add the sliced leeks. Stir gently, cover the pot, and cook for 5 minutes to allow them to release some moisture. Remove the lid and give everything a gentle stir.

Add the rinsed rice, salt, and black pepper. Pour in the orange juice, lemon juice, and water. Stir carefully.

Cover and cook over low heat for 20–25 minutes, or until the leeks are tender and the rice is fully cooked. Stir once or twice during cooking to ensure nothing sticks.

Taste and adjust seasoning. Add more lemon juice if desired.