Preheat oven to 375°F.
Melt 2 tablespoons Challenge Spreadable Butter with Olive Oil in a 10-inch oven-safe skillet. Stir in onion and season with salt and pepper. Cook over medium heat, stirring occasionally, until very soft and golden, about 20 minutes. Remove from heat, spread into an even layer and let cool slightly.
Grab 1 slice of sweet potato, parsnip, and beet and arrange them vertically in the skillet, nestled into the caramelized onions. Continue to arrange vegetable slices, following the same pattern, in concentric circles around the edge of the skillet. Repeat pattern in a smaller circle in the center to fill up the pan. Spread surface with remaining ¼ cup Challenge Spreadable Butter with Olive Oil and sprinkle with ½ teaspoon kosher salt, ¼ teaspoon black pepper, and Panko breadcrumbs.
Cover tightly with foil and bake 30 minutes. Remove foil and roast, uncovered, until vegetables are tender and breadcrumbs are crispy and browned, another 25-30 minutes. Serve warm.