Farro and Green Bean Tuna Salad

Name: Farro and Green Bean Tuna Salad
Ingredients: ½ cup uncooked farro; ¾ tsp salt, divided; 4 cups water; 2 cups (2-inch) cut green beans (about ½ lb); 3 tbsp extra-virgin olive oil; 2 tbsp white wine vinegar; 1 tbsp fresh lemon juice; 1 tsp dijon mustard; 1 small garlic clove, minced; ¼ tsp freshly ground black pepper; 1 cup grape tomatoes, halved lengthwise; ⅛ cup thyme, chopped; ¼ cup kalamata olives; 5 green onions, thinly sliced; 2 jars oil-packed tuna, drained; Feta cheese, to taste