Spinach Artichoke Dip

1 Stick Butter
1/2 Onion
1 pkg Parmesan Cheese
1 cup mozzarella Cheese - 1/2 additional cup of cheese for later
1 can quartered artichoke hearts
1/2 can spinach

sautee onion in butter. Add cheese (both) to onions.  Cut up the artichoke hearts a little more.  Drain the spinach.  I actually probably only use 1/4 of the can.  I start light and add more if needed.  cut up the spinach a little bit too.  Once the cheese is melted add the artichoke hearts and spinach.
If you are putting it in a sprayed crockpot just dump it in and heat.  If you want to bake, put into a sprayed cassarole dish and top with additional mozzarella cheese. bake at 350 for probably 20 min or so.  Just until the top cheese starts to turn a little browned.
Serve with Tortilla Chips or Triscuts are good too!