Heat oven to 350° F.
In large, microwavable bowl, heat cream cheese and sour cream on high 1 minute, or until cheese is softened. Remove from microwave. Mix with wire whisk until smooth. Add refried beans, green chilies, seasoning mix and 2 cups cheese; mix well.
Spread bean mixture into 13-by-9-inch baking dish sprayed with nonstick cooking spray. Sprinkle with remaining cheese. Bake 25 minutes, or until cheese is melted.
Top with cilantro, tomatoes, sliced olives and avocado, if desired. Serve with tortilla chips.