Bring a large pot of salted water to a boil over high heat. Add the sweet potato pieces, once it comes back to a boil, reduce the heat to medium; simmer for about 10 minutes, until almost tender and a knife can go through without breaking a piece. Drain, and transfer to a baking dish large enough to hold the pieces almost in a single layer.
Preheat oven to 400 degrees.
Whisk together orange juice, oil, sugar, salt and pepper in a medium bowl. Pour the mixture over the sweet potatoes and toss to coat evenly. Roast for about 20 minutes, turning them after about 10 minutes, until the potato pieces have started to brown and the sauce has thickened. Remove from the oven.
Meanwhile, cook the chorizo in a medium skillet over medium-high heat; use a wooden spoon of spatula to break it into smaller pieces as it cooks. After 5 to 6 minutes, when it has nicely browned and crisped, use a slotted spoon to top the hot sweet potatoes.
Sprinkle the jalapeño, red onion and cilantro on top, and toss gently to combine. Serve warm.