Heat a large skillet on medium heat. Once hot add enough olive oil to coat the pan.
Add leeks and sweet potatoes to the pan, season with salt and pepper, and fry until the sweet potatoes are slightly browned, for about 3 minutes. Stir occasionally. Reduce the temperature
to medium/low and cover with a lid. Cook until the sweet potato is cooked through, about 5 minutes, and stir occasionally.