Separately, peel and dice a beetroot, setting aside the beet greens for later. Toss the beets with a tiny bit of oil, salt and pepper. Roast alongside but in a separate pan from the squash--or the beets will discolor the squash. Also, I found that the beets roasted more quickly than the squash.
Remove from the oven, loosen from the pan while hot (or it'll stick like mad and the shape of the pieces will be lost), and let cool.
Julienne the beet greens, kale, and spinach. (That means slice it into little ribbony bits.) For greater fennel flavor, sliver additional fennel bulb, and add the feathery fennel fronds from the top of the bulb. Toss all the ingredients together in a large bowl and add a handful of dried cranberries. An additional tiny drizzle of oil (hazelnut would be yummy) adds richness and more depth of flavor; a pinch of fresh orange or lemon zest will bring brightness.
Optional additions: toasted pecans or pine nuts, shredded cooked chicken, fresh pomegranate arils.