Meanwhile, heat 3 tablespoons of oil in a large nonstick skillet over medium-heat. Add the 10 cloves of garlic (reserving 1 clove for the dressing), and cook, stirring frequently, until tender, about 5 minutes. Adjust the heat as needed to make sure the garlic does not burn, or else it will become extremely bitter. When the garlic is tender, increase the heat to medium and add the frozen greens. Sauté, stirring frequently, until cooked through, about 10 more minutes. Transfer the greens to a separate bowl & season with salt & the juice of ½ lemon. Wipe out the skillet with a dry paper towel and return to the stove.