Spinach Artichoke Dip - Oryana

Ingredients

• 1 small onion, coarsely chopped
• 1/2 cup sour cream
• 4 oz cream cheese
• 1 tablespoon mayonnaise
• 1 clove garlic, chopped
• 1 cup shredded aged cheese (extra sharp cheddar, aged provolone)
• 1 cup gently packed fresh spinach
• 1 14-oz can artichoke hearts, drained
• 1 cup shredded Parmesan cheese, divided