Shrimp ‘N’ Shells Salad

Ingredients

• 8 ounces uncooked small pasta shells
• 1 cup fat-free mayonnaise
• 1/4 cup grated Parmesan cheese
• 1/4 cup buttermilk
• 1/3 cup finely chopped onion
• 2 tablespoons minced fresh parsley
• 1-1/2 teaspoons minced fresh basil
• 1/2 teaspoon salt
• 1/2 teaspoon pepper
• 1 pound cooked medium shrimp, peeled and deveined
• 1/4 cup frozen peas, thawed
• 1/4 cup diced pimientos
• 1 medium tomato, seeded and chopped
• 2 green onions, thinly sliced