6 tablespoons plain fat-free yogurt |
2 tablespoons low-fat sour cream |
1 1/2 teaspoons chopped fresh dill |
1 teaspoon lemon juice |
1/8 teaspoon salt |
1 teaspoon vegetable oil, divided |
4 medium zucchini, cut lengthwise into 1/4-inch-thick slices (about 1 1/2 pounds) |