• Clean and remove any brown or yellow leaves from the Brussels sprouts, then slice or shave them as thin as possible. You can do this with a knife but a mandoline slicer will make it MUCH easier. Add them to a bowl.
• Remove the tough stems from the kale, then stack the leaves and roll them up like a cigar. Run your knife through them to make nice, thin ribbons, then add them to the bowl with the Brussels sprouts.
• Drizzle with a tablespoon of olive oil, sprinkle with salt, then use clean hands to squeeze and massage the greens until they're fully coated with oil and have reduced a bit in volume.
• Add the apples, toasted pecans, dried cranberries, cheddar cheese, and bacon.
• In a small bowl, whisk together the shallot, apple cider vinegar, Dijon mustard, honey, salt and pepper. Slowly stream in the remaining 3 tablespoons olive oil and bacon fat while whisking until the vinaigrette is emulsified. Taste and adjust seasoning as needed. 
• Pour the vinaigrette over the salad and toss until everything is thoroughly combined. Serve immediately.

Prep the salad ahead:

• Mix the dressing in a jar and refrigerate until needed. Dressing can be made up to 5 days in advance. Let it come to room temperature for at least 1 hour prior to serving so the fat isn't hardened. 
• Cook the bacon, crumble it and refrigerate in a container. Reserve the fat in a jar and reheat to liquify before serving. 
• Shave the Brussels sprouts and thinly slice the kale. Add it to a zip-top bag with a damp paper towel and refrigerate for up to 3 days in advance.
• Toast and chop the pecans, add to a container along with the dried cranberries and store at room temperature. 
• Dice the cheddar, place it in a container and refrigerate. 
• When ready to make the salad, all you have to do is dice the apples, massage the kale and toss everything together with the dressing.