White Cheese Dip

I wanted to make new recipes for New Year's Eve this year and found this one right away.  My friend pinned it as well and was thrilled when I told her I was making it.  It was very good but I wish I had not used the baking stone dish.  It didn't get a creamy as I would have liked it and was hard to eat.  I used the stone because I wanted it to stay hotter longer.  I think I will use a regular baking dish next time. 

White Cheese Dip
2 blocks cream cheese, softened
1/2 cup chopped onions
1/2 c mayo
1 (8oz) pkg shredded Parmesan cheese
1 (8oz) pkg shredded Monterrey jack cheese

Mix all together with fork.  Spoon into pie pan or baking dish.  Bake at 425 degrees for 20 minutes.  Serve with tortilla chips.