In a jar, combine olive oil, apple cider vinegar, honey, and Dijon mustard. Season with salt and pepper. Shake vigorously until emulsified. Set aside.

Preheat oven to 180°C (350°F). Spread walnuts on a baking sheet and toast for about 8 minutes until fragrant.

Slice pears in half, remove core, and cut into thin slices.

In a salad bowl, add arugula and a drizzle of dressing. Toss lightly. Layer pear slices and blue cheese on top, then sprinkle with toasted walnuts.

Drizzle remaining dressing before serving and gently toss to combine.