shredded mozzarella cheese, dairy sour cream, mayonnaise or salad dressing, parmesan cheese, divided, dijon-style mustard, white pepper (i used black myself), artichoke hearts, drained and coarsely chopped (non-marinated ), loosely packed, coarsely chopped spinach leaves (i used 1 box frozen spinach that had been thawed and drained well by squeezing), chopped red onion (1 medium)