Slice the Brussels sprouts as thinly as possible with a sharp knife. If necessary, you can use the slicing disc on a food processor, but it won’t be super thin. Place in a serving bowl.
Add the apple, Manchego and almonds to the shredded Brussels sprouts.
In a small bowl or in a jar with a screw-top lid, combine all dressing ingredients until emulsified. Add drizzle enough dressing onto the sprouts mixture to coat lightly. Toss to combine well and taste for seasoning.