Preparation Line heavy medium skillet with lemon slices. Sprinkle tuna with salt and pepper and place atop lemon. Add just enough olive oil to cover tuna. Poach tuna over medium-low heat until almost cooked through, about 3 minutes. Using slotted spoon, transfer tuna to plate. Discard lemon slices. Discard all but 1 tablespoon drippings from skillet. Add green onion and sauté over medium-high heat 1 minute. Add escarole, lima beans, and 3 tablespoons parsley to skillet. Sauté until escarole begins to wilt, about 1 minute. Sprinkle with vinegar. Season to taste with salt and pepper. Divide escarole-bean mixture between 2 plates and top with tuna slices. Sprinkle with remaining 1 tablespoon parsley and serve.
Preparation Line heavy medium skillet with lemon slices. Sprinkle tuna with salt and pepper and place atop lemon. Add just enough olive oil to cover tuna. Poach tuna over medium-low heat until almost cooked through, about 3 minutes. Using slotted spoon, transfer tuna to plate. Discard lemon slices. Discard all but 1 tablespoon drippings from skillet. Add green onion and sauté over medium-high heat 1 minute. Add escarole, lima beans, and 3 tablespoons parsley to skillet. Sauté until escarole begins to wilt, about 1 minute. Sprinkle with vinegar. Season to taste with salt and pepper. Divide escarole-bean mixture between 2 plates and top with tuna slices. Sprinkle with remaining 1 tablespoon parsley and serve.