Preheat oven to 425 degrees Fahrenheit (220 degrees Celsius). Place sweet potato cubes and diced red onion on a baking sheet. Drizzle with olive oil and sprinkle with salt and pepper, to taste.

Place baking sheet in the oven and roast sweet potato and onion for 20–25 minutes, or until done.

Combine roasted sweet potatoes and red onion with mixed greens, cucumber, and red cabbage, if using, in a bowl. In a separate bowl, combine dressing ingredients and mix well. Toss salad with dressing. Top with toasted pine nuts and pomegranate seeds immediately before serving.