Rigatoni With Tuna

Ingredients

• 1 lb. rigatoni pasta, cooked al dente and drained
• 9 oz. tuna (2 small cans), drained
• 1 c. sliced black olives
• 1 c. cherry tomatoes, halved and seeded
• 1 small red onion, diced
• 4 stalks celery, 1/4-inch dice
• 1 bottle Italian dressing
• 1/2 tsp. oregano
• salt and pepper to taste