Last year, McDonald’s began testing their Shakin’ Flavor Seasoning in St. Louis and in parts of California. It was originally offered with French fries, but was later an option with Chicken McNuggets. How the Shakin’ Flavor Seasoning works is explained in the image above.

French fry seasoning packets aren’t new to McDonald’s, they’re a popular item in the Asian market. Here in the U.S., the seasoning packets originally came in three flavors — Garlic Parmesan, Spicy Buffalo, and Zesty Ranch. But McDonald’s has also been testing a Chipotle BBQ flavor.

Testing has been going on for almost a year, but there hasn’t been any news of plans to roll out McDonald’s Shakin’ Flavor Seasoning nationwide.

If you’ve tried any of the flavors, share your thoughts in the comments.

(Thanks for the photo Benjamin!)