Oven Roasted Sweet Potato Cubes. We buy a lot of sweet potatoes in our house. For one, they are easy to find and inexpensive: both important considerations when on a budget. But also, sweet potatoes are versatile, have some health advantages, and our kids will eat them. We love making sweet potato fries and these roasted sweet potato cubes. We roast them in the oven until they get a good crisp...crispy sweet potatoes are better than mushy sweet potatoes. Easy prep, simple seasoning, enjoy!