In large salad bowl, mix salad greens, croutons, Parmesan cheese, bacon, and celery. Lightly toss til mixed.
For peppercorn dressing, in a blender container, mix 1/2 cup of the oil, egg, vinegar, onion, peppercorns, and salt. Cover and blend on low speed for 5 seconds. With blender running on low speed, add remaining 1 cup oil in a thin steady stream, stopping to scrape sides when needed. Pour 10 to 12 tablespoons of the peppercorn dressing over salad mixture. Cover and store remaining dressing in the fridge up to 2 weeks. Lightly toss til coated. makes 4 to 6 side dish servings.