Adjust an oven rack to the middle position and heat the oven to 400°F. Toss the sweet potatoes with oil and season with salt and pepper on a rimmed baking sheet. Arrange the potatoes in a single layer and roast until the bottom edges are browned, about 25 to 30 minutes, flipping the potatoes halfway through. Transfer them to a plate and let cool for 20 minutes so they don't wilt the greens too aggressively.

Vigorously squeeze and massage the kale with your hands for about 1 minute. You'll know it's ready when the leaves are uniformly darkened and feel slightly wilted.

Whisk the water, pomegranate molasses, shallot, honey, vinegar, salt, and pepper together in a large bowl. Drizzle in the oil while whisking constantly to create a smooth, emulsified dressing.

Add the cooled roasted potatoes, massaged kale, and radicchio to the bowl with the vinaigrette and toss gently to coat. Transfer to a platter and sprinkle with pecans and shaved Parmesan. Serve immediately.