Meanwhile, in a large skillet over medium-high heat, heat 1 tablespoon oil. Add garlic and mushrooms; sauté 5–6 minutes or until mushrooms are tender and liquid has cooked off. Remove mushrooms to a plate, and set aside. Add remaining 1 tablespoon oil to same skillet, and reduce heat to medium. Add cabbage and sauté, stirring often, for 8 minutes. Add sliced zucchini and salt to skillet with cabbage. Continue to sauté until cabbage begins to brown and zucchini is tender but still bright green, about 8 minutes.