Pour the dip into an 8-inch square baking dish
and bake for 15-20 minutes until bubbly. If using shredded cheddar cheese, sprinkle the cheese on top before baking. If using crumbled blue cheese, sprinkle the blue cheese on top as soon as you remove the dip from the oven. Garnish with sliced scallions. Serve with baked pita chips or celery and carrot sticks.