Wash the potatoes and dice them roughly. Cover and cook in salted water for about 10 minutes. Finely dice the onion. Wash the bell peppers and cut into small pieces. Drain tuna and chop coarsely
Drain the potatoes well. Heat the oil in a coated pan. Fry the potatoes, onion and peppers for about 5 minutes, turning them over. Season with salt, pepper and sweet paprika
Whisk the egg, 3 tablespoons of water, salt and pepper. Wash and chop the parsley and stir it in. Add tuna to the potatoes. Pour the egg over the potatoes and let it simmer for about 8 minutes at medium heat, if necessary covered.