Bring a large pot of salted water to a rapid boil. Add the escarole and cook until tender but firm, about 5 minutes after the water returns to the boil. Remove the escarole with a slotted spoon, place in a bowl, and set aside. Reserve * cup of the cooking water. Set aside. (The escarole may be parboiled and set aside several hours before proceeding with the recipe.) Warm the olive oil in a large saute pan set over medium heat. Add the garlic and cook to flavor the oil but do not let it brown, about 2 minutes. Add the escarole and the reserved cooking water. Cook, stirring occasionally, to warm through and bring the flavor of the garlic and escarole together, about 4 minutes. Serve immediately.