Heat oil in a large skillet or sautee pan over medium-high heat. Once hot, add the Brussel sprouts. Carefully, shake pan so most cut sides of sprouts facing down in the oil. Cook undisturbed for about 5 minutes, until cut sides of sprouts become caramelized.
Stir and continue to cook until sprouts have taken on a caramelized color and start to char. Cook for another 5 minutes or so until they are tender. Season with lemon juice, onion powder, salt and pepper. Stir and cook another minute.
Remove from heat, toss in toasted pistachios and transfer into a serving dish. Top with lemon zest.
Notes
* Cooking time may very slightly if your Brussel sprouts a on the bigger side. Keep an eye on them.