Place the chicken stock, onion, carrot, celery, bell pepper, butter, salt, black pepper, and crushed red pepper in a 6-quart.
Cover and cook on HIGH until vegetables are tender, about 3 hours.
Using a hand blender/kitchen emulsifier or blender, pulse the mixture to break up the tender vegetables.
Whisk Cheddar cheese with 1 tablespoon of the cornstarch.
Cream the cream cheese and 1 cup of the milk.