In a large bowl, whisk together lemon juice, sumac, mustard, shallot, and anchovy. Gradually whisk in oil until thick and emulsified; season with salt and pepper. Add celery and toss to coat; season with salt and pepper. Cover and chill to allow flavors to meld, about 1 hour.
Add cheese, parsley, and pine nuts to salad and toss to combine; adjust seasoning and serve.