I like to mix lemon juice and orange juice in my vinaigrettes, but you can also use all lemon or all orange juice and zest in this version. Other vegetables can be substituted for the zucchini in this recipe: Asparagus cut into 1-inch pieces, or yellow squash, bell peppers or small broccoli florets to name a few. Just don’t use very dense veggies like winter squash or potatoes. If you use frozen vegetables, make sure to defrost them first and pour off excess liquid before adding them.