Place a large, deep skillet over medium heat. After a minute, add half the remaining olive oil, and swirl to coat the pan. Toss in half of the greens, turn the heat up to medium-high, and stir-fry, turning with tongs, for about 5 minutes, or until wilted. Stir in half the fresh garlic, sprinkle lightly with salt, if desired, then transfer to a medium-sized bowl, and set aside. Repeat this step with the remaining olive oil and greens.