Buttermilk Dressing~Ranch

• 1 cup mayonnaise
• 1/2 cup buttermilk
• 2 tablespoons freshly squeezed lemon juice
• 1 teaspoon coarse salt
• 1 teaspoon celery seed
• 1 tablespoon finely chopped fresh oregano or 1 teaspoon dried
• 1/4 teaspoon freshly ground black pepper
• Pinch of cayenne pepper (optional)