Preheat oven to 425 degrees.

Trim the stems on the Brussels sprouts, remove the outer leaves and cut in half.

In a large bowl, combine the Brussels sprouts with 1 tablespoon of olive oil and kosher salt, and toss to coat. 

Transfer the Brussels sprouts to a lightly oiled sheet pan and roast, stirring occasionally, until they are golden brown, about 20 minutes.

Return the Brussels sprouts to the bowl and add the balsamic vinegar and remaining 1 tablespoon olive oil, tossing again to coat. Sprinkle on the Green Za'atar and season to taste with freshly ground black pepper.

Transfer the roasted Brussels sprouts to a serving dish and garnish with nigella seeds.