Preheat oven to 400°F. Line a 15x10x1-inch baking pan with parchment paper; set aside. In a medium bowl, toss the parsnips and carrots with 2 tablespoons of the olive oil and half of the salt and pepper. Transfer to prepared baking pan, spreading in a single layer. Roast, uncovered, for 20 minutes or until tender. Remove and cool in baking pan on a wire rack. To store, place in a storage container and chill up to 24 hours.
In a small bowl, whisk together the remaining 1/2 cup oil, remaining salt and pepper, shallots, lemon zest, lemon juice, vinegar, honey, and mustard until well-combined (you should have about 1 1/4 cups). Use immediately or cover and chill up to 24 hours. Shake before using.
Meanwhile, heat a 10-inch skillet over medium heat. Add bacon strips and cook until browned and crisp. Remove to paper towels to drain. Chop the bacon and set aside. To store, place in a storage container and chill up to 24 hours.
Up to six hours before dinner, toss together the kale, vinaigrette, root vegetables, bacon, and currants; chill. Bring to room temperature 1 hour before serving. Place on a large serving platter or shallow bowl.