Preheat oven to 425 degrees F. Bring a large pot of salted water to a boil for the pasta.
Peel the sweet potato and chop into ½-inch pieces; place in a microwave- and oven-safe baking dish. Toss sweet potatoes with 2 tablespoons olive oil, ¼ teaspoon salt, and a few grinds of black pepper. Microwave on high for 5 minutes, stirring halfway through. Transfer the dish with the sweet potatoes to the oven, being careful as it will be hot. Roast potatoes for 13-15 minutes, until tender.
When the pasta water is at a boil, add the pasta and cook according to package directions for al dente. Drain pasta and return to the pot.
Meanwhile, in a small bowl, whisk together the dressing ingredients and set aside.
Drain and rinse the chickpeas.
To the pot with the cooked, drained pasta, add the arugula, chickpeas, and dressing; stir to combine. Gently stir in the sweet potatoes, pepitas, and cherries or cranberries. Serve topped with crumbled goat cheese. This dish can be enjoyed warm or cold.