Niçoise Pasta Salad

Name: Niçoise Pasta Salad
Ingredients: 8 ounces cavatelli or other short pasta; 1 teaspoon kosher salt, plus more for pasta water; 10 ounces small red potatoes (8 to 10), quartered; 4 large eggs; ½ cup extra-virgin olive oil; 2 tablespoons balsamic vinegar; 1 teaspoon Dijon mustard; ½ teaspoon soy sauce or tamari; 1 5-ounce jar tuna packed in oil, drained and broken into pieces; ½ cup chopped pickled green beans; ½ cup sliced radishes (about 4 oz.); ⅓ cup pitted Niçoise olives; ¼ cup chopped flat-leaf parsley, plus more for serving