Preheat the oven to 425ºF. Peel and slice the sweet potatoes into 1/2 inch wide sticks. Place the sweet potatoes on a large baking sheet and drizzle with olive oil. Sprinkle the cumin and salt over top.
Pull the cilantro leaves from the stems and roughly chop. Add about 3/4 of the cilantro to the baking sheet with the sweet potatoes, reserving some to add fresh after baking. Toss the sweet potatoes until they are evenly coated in oil, cumin, salt, and cilantro.
Roast the sweet potatoes in the oven for 20 minutes, stir, and return to the oven. Roast for about 15 minutes more, or until the sweet potatoes are blistered and browned on the edges.
After roasting, add the remaining cilantro and squeeze fresh lime juice over top. Serve warm.
SERVING SUGGESTION: Serve alongside tacos, enchiladas or even alone as a snack.