Herbed Farro Salad with Walnuts, Feta and Spinach

Name: Herbed Farro Salad with Walnuts, Feta and Spinach
Cuisine: Mediterranean, Greek, European
Ingredients: 1 cup semi-pearled farro; About 3 cups water, or more as needed; 1/3 cup walnut pieces; 2 cups lightly packed baby spinach leaves, chopped; 1/2 English cucumber, peeled and diced; 3 ounces feta cheese, crumbled (2/3 cup); 1 scallion, white and green parts, thinly sliced; 1/4 cup fresh flat-leaf parsley leaves, chopped; 3 tablespoons fresh dill fronds, chopped; 2 tablespoons extra-virgin olive oil; 2 tablespoons fresh lemon juice; 1/4 teaspoon kosher salt; 1/8 teaspoon freshly ground black pepper