Preparation Over medium heat, place a skillet lare enough to hold all the tuna steaks in one layer. Add 2 tablespoons of the olive oil, the sliced onions, salt, and pepper to taste. Cook the onions for about 8 to 9 minutes or until they're wilted and golden brown. Remove the onions from the pan and keep them warm. Add 2 more tablespoons of the olive oil to the same pan and increase the heat to high. Season the tuna steaks with salt and pepper and lightly flour them on both sides. Sear the tuna steaks for 2 minutes on each side, then remove them from the pan. Add the sugar, vinegar, wine, and cooked onions to the pan. Cook uncovered, over medium heat for about 2 minutes. Add the parsley and the tuna steaks and cook for another 2 mintues. Remove the tuna to a warm platter, pour the pan juices on top, and serve.
Preparation Over medium heat, place a skillet lare enough to hold all the tuna steaks in one layer. Add 2 tablespoons of the olive oil, the sliced onions, salt, and pepper to taste. Cook the onions for about 8 to 9 minutes or until they're wilted and golden brown. Remove the onions from the pan and keep them warm. Add 2 more tablespoons of the olive oil to the same pan and increase the heat to high. Season the tuna steaks with salt and pepper and lightly flour them on both sides. Sear the tuna steaks for 2 minutes on each side, then remove them from the pan. Add the sugar, vinegar, wine, and cooked onions to the pan. Cook uncovered, over medium heat for about 2 minutes. Add the parsley and the tuna steaks and cook for another 2 mintues. Remove the tuna to a warm platter, pour the pan juices on top, and serve.