Marinate steaks in 1/2 cup dressing in large plastic food-storage bag in the refrigerator for 2 hours.
Cook potatoes following package directions, using 2 tablespoons vegetable oil, 1/2 teaspoon salt and 1/4 teaspoon black pepper, 15 minutes.
Place cooked potatoes in large bowl; stir in 1/4 cup dressing. Cover; let stand at room temperature.
Meanwhile, heat broiler or grill. Broil or grill steaks 2 to 3 minutes per side for medium-rare (145 degrees F). Let steaks stand 5 minutes. Serve with potatoes. Makes 4 servings.