Start by rinsing the farro under cold water to remove any excess starch. Add it to a saucepan with water and a pinch of salt, then bring to a boil. Reduce to a simmer and cook until tender but still pleasantly chewy, about 25–30 minutes, then drain and let it cool slightly.
While the farro cooks, finely chop the kale and place it in a large bowl. Drizzle a small amount of olive oil and add a pinch of salt. Massage the kale with your hands for a few minutes until it softens and darkens in color.
In a small bowl or jar, combine olive oil, fresh lemon juice, Dijon mustard, honey, salt, and pepper. Whisk or shake until the dressing becomes smooth and slightly thickened. Taste and adjust seasoning if needed.
Add the cooked farro to the bowl with the massaged kale. Stir in chopped parsley, mint, red onion, and pistachios. Pour the dressing over the salad and toss thoroughly to ensure everything is evenly coated.
Allow the salad to sit for about 10–15 minutes before serving. This helps the flavors meld beautifully. Give it one final toss and adjust salt or lemon if necessary before plating.