Remove any thick stems from the spinach. Soak the spinach in water to loosen any sand or dirt, then drain and repeat. Place the cleaned spinach in a salad spinner to remove any excess moisture.
Peel and thinly slice the garlic. Heat half the olive oil in a large frying pan (skillet) on medium high heat then add the garlic and sauté for about 1 minute, until the garlic is just beginning to brown.
Add the spinach to the pan, packing it down with your hand. Use a couple spatulas or wooden spoons to lift the spinach and turn it over so that it gets well coated with the olive oil and garlic. Turn a couple of time then cover the pan and cook for one minute. Uncover and turn the spinach again. Cover the pan and cook for an additional one minute.
After 2 minutes of covered cooking the spinach should be completely wilted. Remove from the heat and drain any excess moisture from the pan. Pour over the remaining olive oil, sprinkle with salt and freshly ground black pepper to taste and serve immediately.