1Remove the ribs and thinly slice the leaves of kale (I do this by stacking or gathering them up in a bunch, then slicing through the stack); cut the Brussels sprouts in half lengthwise and thinly slice them too, holding onto the stem (and then tossing the last bit of stem out). Put them into a bowl with the purple onion.
2To make the dressing, shake all the ingredients together in a jar or whisk them in a small bowl. Drizzle generously over the kale and Brussels sprouts and toss to coat. Scatter with almonds and Parmesan and serve.