Preheat oven to 500 degrees F.
Wash and cut Brussels sprouts in half lengthwise.
In a bowl add 2 Tablespoons olive oil, water and salt. Add Brussels sprouts and toss to coat.
Place Brussels sprouts, cut side down on a baking sheet. Cover tightly with foil and roast for 10 minutes.
Remove foil and continue to cook for an for 10 minutes or so depending on the size of the sprouts.
While Brussels sprouts are roasting, in a small sauce pan, heat additional 3 Tablespoons olive oil until shimmering. Add garlic and crushed red pepper flakes. Remove from the heat.
When the Brussels Sprouts are done, toss with the oil and fresh parmesan cheese. Season to taste with additional kosher salt and black pepper if necessary.