1 Place zucchini and garlic into a steamer basket, then place the steamer basket into the pot. 2  Steam for 10 to 15 minutes, or until the zucchini are tender. 3  Transfer zucchini to a large bowl.4  Mash the garlic and put it in the bowl with the zucchini.irections. Prep. Cook. Ready In. 1  Bring a large pot of water to a boil. 2  Trim ends from zucchini. 3  Cut each one in half, then cut each half lengthwise into quarters. 4  Place zucchini and garlic into a steamer basket, then place the steamer basket into the pot. 5  Steam for 10 to 15 minutes, or until the zucchini are tender.