This is from the weather guy on KSDK- he made it on Memorial Day and it looked awesome!!
Vidalia hot onion dip
1 large Vidalia onion chopped into fine pieces (about 4 cups)
1 Package mozzarella cheese
1 cup mayonnaise
1 cup grated Parmesan cheese
Combine chopped onion, mayonnaise and mozzarella cheese.
Spread into a baking dish and cover with Parmesan cheese.
Back at 350 degrees for 30 to 45 minutes until it is bubbly and browned to your liking.
We served the dip with Ritz crackers.