To make a veggie tuna salad, first you'll need to prepare the ingredients. First, you will need: 1 pound romaine lettuce, 2 tbsp. mayonnaise, 1/2 cup chopped scallions, 1 chopped red bell pepper, 1/4 cup diced tomatoes, and 1 teaspoon each kosher salt and freshly ground black pepper. Toss the lettuce with 2 tablespoons each olive oil and balsamic vinegar. Cover the salad with plastic wrap and refrigerate until ready to serve.