With a mandolin or vegetable peeler, slice sweet potatoes lengthwise as thinly as possible. Cut each slice into ¼-inch strips; set aside.

In a saucepan over medium heat, melt butter. Add sage; cook until crisp. Remove to paper towels to drain.

Add sweetpotato strips to remaining butter in pan. Cook and stir until al dente.

Crumble 2 of the reserved sage leaves over sweetpotato; stir.

To serve, garnish with remaining sage leaves.