Toss Brussels sprouts with olive oil, garlic powder, black pepper, agave, and Sel Magique. Spread onto a 9x13-inch baking pan.
Roast in the preheated oven, shaking every 5 minutes, until crispy and fork-tender, about 20 minutes. Toss with balsamic vinegar and sprinkle with Parmesan. Continue roasting until melted, about 1 minute more.
Remove, and serve - add a little more Sel Magique as desired. Enjoy!