Preheat oven to 350 degrees.
In a mixing bowl, combine cream cheese, sour cream and shredded cheese with a hand mixer, reserving some of the shredded cheese for topping, and mix until well combined.
Remove boudin from casing and break into the cheese mixture. (Keep boudin refrigerated until preparing, as cold boudin will mix better.) Spread mixture in 1-quart baking dish.
Top with remaining cheese and bake at 350 degrees until cheese is melted and bubbly, about 30 minutes.
Serve with warm bread, crackers, or chips.