Bring the salted water to a boil. Add the lima beans and cook for five minutes, or until tender but firm. Drain and rinse in cold water, then drain again. Pat dry with paper towels.
Transfer the lima beans to a medium mixing bowl. Stir in the oil, lemon zest, and the lemon juice. Season with salt and pepper to taste. Place in a serving bowl and top with the Parmesan cheese.