Rinse and pat dry brussels sprouts. Trim off the stems and remove and discard any dry or wilted leaves. Shave brussels sprouts with your desired method* and place them in a large bowl.
Top the shaved Brussels sprouts with chopped apple, cranberries, parmesan cheese, sunflower seeds, and chives.
In a separate bowl, whisk together the dressing ingredients: olive oil, lemon juice, dijon mustard, salt, and pepper.
Just before serving, pour the dressing over the salad and toss to combine.