Preheat oven to 400 F. Line a large sheet pan with parchment paper.
Scrub the sweet potatoes and chop, about a half-inch dice.
Peel, clean and chop the onion, about a half-inch dice.
In a large bowl put the diced potatoes, onions and the rest of the ingredients except the corn.
Pour the potato mixture onto the large sheet pan spreading evenly and bake in the oven for 30 minutes. Remove sheet pan and add the corn giving the mixture a stir. Lower the heat to 350 F and return to the oven for 15 minutes or until done.