Zucchini with Lemon-Dill Cream

6 tbsp plain fat-free yogurt
2 tbsp low-fat sour cream
1-1/2 tsp chopped fresh dill
1 tsp lemon juice
1/8 tsp salt
1 tsp vegetable oil, divided
1-1/2 pounds zucchini, cut lengthwise into 1/4-inch-thick slices

Combine first 5 ingredients in a small bowl.
Heat 1/2 tsp oil in a 12-inch cast-iron skillet over high heat. Add half of zucchini slices; cook 2 minutes on each side or until browned. Remove zucchini from skillet, keep warm. Repeat procedure with 1/2 tsp oil and remaining zucchini slices. Serve with yogurt mixture.