1- Heat oil in a large skillet over medium-high heat. Add Brussels sprouts, season with salt and freshly ground black pepper, and saute until browned; about 5-8 minutes.
2- Add 1/3 cup water and 1 tsp lemon zest (optional). Continue to cook until the water has cooked off and the sprouts are tender; about 5 minutes.
3- Toss with 1 tbsp lemon juice, place in a serving bowl and top with shaved Parmesan.