Boil 1 bunch quartered baby turnips in 4 cups salted water, 5 minutes. Add the chopped turnip greens and 1/2 cup frozen lima beans; cook 2 minutes. Remove the vegetables with a slotted spoon. Add 3/4 cup instant grits to the water; add salt and cook, stirring, until thick, 5 minutes. Stir in the vegetables and 1 tablespoon butter. Season with pepper.