Combine all ingredients for Honey-Dijon Dressing in a small jar. Set aside to allow flavours to blend.
Preheat oven to 400°F. When hot, place a baking tray in the oven to heat. Peel sweet potatoes and cut into rounds ½ inch thick. If potatoes are large, slice into half circles or even quarter circles. In a medium bowl, toss with 1 ½ teaspoons of olive oil, sprinkle lightly with salt and pepper. Remove the hot tray from the oven using oven mitts and arrange the sweet potatoes so they don't touch each other. Return the baking sheet to the oven. Roast for 20 - 25 minutes or until tender, turning over half way through roasting time. For crispy edges, place under the broiler for 2 - 3 minutes, watching carefully.
Cook two strips of bacon in a skillet, or bake them in the oven alongside the sweet potatoes. When almost crisp, remove from oven and drain on paper towels.
Toast walnuts in a small skillet for 4 - 5 minutes, just until they become fragrant. Toss with 1 ½ teaspoons pure maple syrup. Let cool on a sheet of parchment paper and break apart when cool.
Wash and dry spinach and chopped romaine. Arrange in bowls or on a serving platter, topping with maple-glazed walnuts, pomegranate arils, roasted sweet potatoes and crumbled bacon bits. Drizzle with dressing and serve immediately.