The egg white just helps the fries from being floppy, although they're not as crispy as they would be if they were fried.
3 whole sweet potatoes, small (or 2 medium/large)
1 egg white
1 tsp kosher salt
1/4 tsp freshly ground black pepper
2 tsp dried rosemary
1/4 tsp cayenne pepper
Preheat oven to 425F. Line a baking sheet with parchment paper. Spray the paper with cooking spray (I use olive oil spray.)
Cut the sweet potatoes into large matchsticks.
In a medium sized bowl, whisk the egg white until foamy. Stir in the salt, pepper, rosemary and cayenne. Add the sweet potato strips and toss.
Arrange in a single layer on the prepared baking sheet and bake 25 minutes. Enjoy.