Preheat oven to 400°F (200°C).
Slice the sweet potato lengthwise into ¼-inch thick slices.
Place slices on a parchment lined baking tray and roast for 20–25 minutes, flipping halfway, until tender.
In a bowl, mash the berries with a fork until slightly chunky (add a little water if needed).
Spoon the berry mash over warm sweet potato slices.