This is a classic combination: a salty-sweet salad of blue cheese, pears, and walnuts.
In a small bowl, whisk together vinegar, salt, and pepper. Slowly whisk in oils; set aside. In a medium bowl, combine whole and cut-up endive, pear slices, walnuts, and cheese. Drizzle with dressing; gently toss to coat evenly. Divide among four salad bowls. Serve immediately.