1. Put eggs in a small saucepan. Cover with hot water and bring to a boil. Remove from heat, cover, and let sit 12 minutes. Drain and rinse eggs with cold water until cool. Peel and quarter.
2. Meanwhile, in a bowl, whisk together oil, lemon juice, salt, pepper, and paprika. Add olives, tuna, onion, and parsley, and stir just to combine, leaving tuna in large chunks.
3. Arrange 2 tomato pieces on each of 4 slices ciabatta. Top with tuna mixture, dividing evenly, and remaining slices ciabatta.
*For the most sustainable choice, look for pole- or troll-caught tuna.
Note: Nutritional analysis is per sandwich.