Tuna Elbow Macaroni with Sweet Pickle Mayonnaise

Ingredients

• 1 cup mayonnaise
• 1/4 cup drained sweet pickle relish
• 1 tablespoon cider vinegar
• 1 teaspoon prepared mustard (I used Dijon)
• 2 cups elbow macaroni
• 1 7-oz can white albacore tuna, drained
• 1/2 cup frozen mixed vegetables, thawed
• 1/2 cup diced celery
• 1/2 cup chopped red onion
• 1/2 cup grape tomatoes, sliced
• 1 green onion, thinly sliced, for garnish (optional)