Tuna Macaroni Salad Classic

Ingredients

• 1 pound elbow macaroni
• 10-12 ounces tuna packed in water, drained
• 4 tablespoons sweet pickle relish
• 1 cup chopped celery
• 2 tablespoons chopped red onion
• 1 cup frozen peas, cooked and cooled
• 4 hard-cooked eggs, chopped
• 1-2 teaspoons prepared mustard
• 1 cup mayonnaise, or more as needed
• Salt
• pepper