Thank you for finally clearing that up! My grocery store has this backwards. On the display, the sign above the sweet potato says "yams". Then when I do self-checkout, I select yams, and I end up getting charged $4.99/lb instead of the .99/lb that the sign said. And I make the same mistake every time! So now I know, because I've never had that thing in the picture on the left-hand side.
Anyway, I cut the sweet potato into french fries, toss with olive oil, salt & pepper, and Cajun seasoning, and roast them.