Toss Brussels sprouts, kale and radicchio with 1 tablespoon (15ml) olive oil on a rimmed baking sheet. Season with salt and pepper. Roast until beginning to wilt and brown, about 6 to 8 minutes, tossing halfway through.
Whisk together shallot, vinegar, Dijon and syrup in a small bowl. While whisking, slowly drizzle in remaining oil. Season with salt and pepper.
Transfer vegetables to a serving bowl. Toss with dressing, sprinkle with cheese, pomegranate and walnuts.