First, make the dressing. In a small bowl, whisk together the olive oil, apple cider vinegar, both mustards and maple syrup. Season with salt and set aside.

Thinly slice the Brussels sprouts using a mandoline or food processor with the slicing attachment. Alternatively, you can use a or sharp knife.

Place the shredded Brussels sprouts in a large bowl, add the green onion and apple and toss with the dressing until evenly coated. Set aside.

In a medium skillet over medium heat, heat walnuts until browned and fragrant, stirring occasionally, about 2 to 5 minutes. Remove from skillet and chop coarsely.

Using the same skillet, heat 1/2 tablespoon olive oil over medium heat. Add the panko bread crumbs and toast, stirring often until golden brown. Transfer to small bowl to cool, then add the grated parmesan. Stir to combine.

Add most of walnuts and panko-parmesan mixture to the bowl with the Brussels sprouts and toss to combine. Serve garnished with the remaining walnuts and panko-parmesan mixture.

Serve and enjoy!