Preheat oven to 425˚F.
On an aluminum-foil or parchment paper lined sheet pan, toss together sweet potatoes, olive oil, maple syrup, cinnamon, salt and black pepper. Spread in an even layer. Bake 30-35 minutes, tossing in between. Allow to cool completely before adding to the salad.
For the dressing, in jar or small mixing bowl, combine mayonnaise, dijon mustard, maple syrup, orange juice, olive oil, salt and black pepper. Once well emulsified, taste for balance of flavors and adjust if desired.
On a large serve tray or on individual salad plate, layer lettuce, cheddar cheese, red onion, apple, pomegranate arils and pecans. Add chicken on top (if using), followed by the cooled roasted sweet potatoes.
When it's time to serve, drizzle dressing over the top or serve on the side.