This is mac and cheese for people who like their comfort food with a little personality. It is creamy, yes, but it also has that tangy, can I-get-another-bite thing going on that makes the cheese taste louder and the whole bowl feel more alive.
The secret is not a mystery ingredient you have to special-order. It is a small hit of acidity and a better method: build a smooth sauce first, then fold in the cheese off the heat so it stays silky instead of grainy. You can keep it stovetop simple, or take five extra minutes to throw it under the broiler for crisp edges. Both are correct choices.