Add the Brussels sprouts, kale, green onions, cranberries, Manchego crumbles, and basil to the bowl with the dressing. Mix until ingredients are fully coated with dressing. Pour the reserved almond-infused oil and almonds over the salad mixture and add remaining black pepper and up to 1.5 tsp. kosher salt. Mix until ingredients are evenly dispersed. If time permits, let stand in the refrigerator 2-4 hours before serving.
TIP A: "Düsseldorf mustard" is just a more specific (and fancier) name for German-style or brown mustard. It's beginning to overtake Dijon as the mustard-of-choice for cooking because it tends to add a bright, complementary suite of flavors vs. the nose-tingling punch of some Dijon varieties. That being said, some Düsseldorf types are pretty punchy as well, so—for this recipe—I recommend looking for a smooth or creamy style. Koops'® is an excellent brand sold in my region and also available on Amazon.
TIP B: The one challenge to making this slaw (like most slaws) is all of chopping, slicing, and shaving. If you're a purist and like the process of preparing your own vegetables by hand, then have at it (I agree, fresh cut is usually the way to go). But, if you want a short-cut without being short-changed on freshness, give Mann's® Power Blend a try. Mann's is a generations-old, women-owned business out of CA—probably best known for their carrots and Broccolini®. I promised to share on this site the brands that I enjoy and trust most, and Mann's is one of them. They're my go-to in the fresh veg department, and their Power Blend is a perfect substitute for the kale in this slaw. Still add more fresh Brussels sprouts as the recipe indicates—they're the star of the slaw after all!
TIP C: I think of Manchego cheese as a Spanish Pecorino Romano, but that probably doesn't do justice to its surprisingly creamy characteristics (despite being considered a hard cheese). When cold, Manchego is extremely firm and crumbles easily. Keep the cheese in the fridge until right before you want to crumble it. Use a fork or clean hands to create mostly pea-size crumbles, but leave a few larger chunks for a bit of indulgence.