A Midwest-based burger chain says it will start cooking its French fries in 100% beef tallow. The change from vegetable oil to beef fat comes after Robert F. Kennedy Jr. called on McDonald's to return to the method it used for decades. Starting in February, Steak n Shake will fry its shoestring fries in beef tallow.

Beef tallow is a flavorful cooking fat obtained by slowly rendering the fat from any cut of beef. Once melted, the tallow is left at room temperature to harden and solidify, achieving a texture similar to butter.

Steak n Shake, an Indianapolis-based fast-food chain with locations across the Midwest, the South and beyond, has announced plans to switch to using “100% all-natural beef tallow” when cooking its french fries,

Beef tallow has long been associated with fast-food french fries, but health trends have mostly prevailed and made beef tallow fries scarce. Discover which fast food chain has decided to start frying their french fries in beef tallow.