Place the sweet potato cubes in a bowl and drizzle with 3 tablespoonfuls of olive then season with salt and pepper and toss until coated. Spread out on a large baking sheet. Roast in the oven about 20 minutes, stirring occasionally, until fork tender.
Wash and dry the kale and remove the stems. Chop into small pieces. Lay on a serving platter and top with roasted sweet potatoes, feta cheese, pecans, dried cranberries, and pomegranate seeds.
Whisk together red wine vinegar, ¼ cup olive oil, salt, and pepper. Drizzle over the salad and serve immediately.