Preheat the oven to 425°F and line a baking sheet with parchment paper.
Place the squash on one side of the baking sheet and the onion wedges on the other. Drizzle with olive oil and sprinkle with salt and pepper. Toss to coat and spread evenly on the baking sheet. Roast for 20 to 35 minutes, or until tender and golden brown around the edges. Remove the onions before the squash if needed. Pull apart the onion layers.
Place the kale in a large bowl and drizzle with some of the dressing. Use your hands to massage the leaves until they become soft and wilted and reduce in the bowl by about half.
Add the radicchio, Brussels sprouts, roasted squash, onions, and remaining dressing. Toss well, then top with the pecans, pomegranates, and cheese. Gently toss. Season to taste and serve.