In a medium pot, simmer 1 cup of farro in 5 cups of water for 25–30 minutes. You want it softened but still slightly chewy. Drain and rinse with cold water to stop cooking and cool the grains.
In a small bowl, whisk together crushed garlic, Dijon mustard, olive oil, and apple cider vinegar. Season with salt and pepper to taste. This simple dressing brings a tangy, nutty flavor that complements the salad perfectly.
In a large serving bowl, combine cooled farro, shredded kale, chopped parsley, celery, and toasted pistachios. Pour the dressing over the salad and toss gently to combine. Serve immediately or chill for later.