Farro with Artichokes and Herb Salad

Name: Farro with Artichokes and Herb Salad
Ingredients: 4 tablespoons unsalted butter; 2 stalks celery, plus ½ cup celery leaves; 1 carrot, diced finely; 1 small celery root, peeled and diced finely; 1 small onion, diced finely; 1 bay leaf; 2 cups (14 ounces) farro; 1 cup dry white wine; 4 cups low-sodium chicken broth; Salt and freshly ground pepper, to taste; 3 tablespoons grated Grana Padano, plus shaved cheese for garnish; 3/4 cups (4 ounces) marinated baby artichokes, drained and halved; 1/2 cup flat-leaf parsley leaves; 1/4 cup snipped chives; 1 tablespoon fresh tarragon leaves; 1 teaspoon white wine vinegar; 1 tablespoon extra-virgin olive oil