1. Preheat broiler. Coat sweet potato fries and steak with cooking spray. Place on separate baking sheets, and sprinkle with 1/4 teaspoon each salt and pepper. Place fries and steak in oven for 20 minutes, turning fries once, halfway through. Steak is done when a meat thermometer inserted into the thickest part registers 160° (medium). Fries should be tender and crisp.
2. Combine yogurt, blue cheese, and remaining 1/4 teaspoon each salt and pepper. Toss lettuce, tomato, and carrot together.
3. Cut steak into strips. Arrange the salad evenly on 4 plates and top with steak. Drizzle dressing over salad; serve with sweet potato fries.