Preheat the fryer. In a large saute pan, with a lid, over medium heat, add the oil. When the oil is hot, crush the bay leaves into the oil. Cook for 30 seconds. Add the onions. Season with salt and pepper. Saute until wilted, about 4 to 6 minutes. Add the garlic, tomatoes and water. Season with salt and pepper. Bring the mixture to a simmer, reduce the heat to medium low, cover and cook for 30 minutes. Season both sides of the tuna with salt and pepper. Add the tuna to the pan, spooning some of the tomato mixture over the steaks, cover and cook until the tuna is tender, about 12 to 15 minutes. Fry the potatoes until golden brown, about 3 to 4 minutes. Drain on paper towels. Season with salt and pepper. To serve, remove the steaks from the pan and place on a serving plate. Add the parsley to the sauce and mix well. Spoon the tomato mixture over the tuna. (**If you want the sauce thinner, add in a little water) Pile the fried potatoes next to the tuna. Garnish with 4 to 5 of the olives and serve.