Chef John's Caramelized Brussels Sprouts

Preheat your oven to its highest temperature setting, 450 degrees F (230 degrees C), for optimal results.

Fill a large container with water and bring it to a vigorous, rolling boil. Submerge the Brussels sprouts in boiling water for 2 minutes, allowing them to partially cook. Utilize a slotted spoon to transfer the sprouts to a bowl of ice-cold water, where they will rapidly cool down. Drain excess water and gently pat the sprouts dry with paper towels before setting them aside.

Add sliced onions to boiling water and cook until they are nearly tender, taking approximately 10 minutes. Once done, drain the onions in a colander and rinse them under cold running water to stop the cooking process. Pat the onions dry with paper towels and set them aside.

Melt butter in an oven-safe skillet over medium heat on your stovetop. Combine the cooked Brussels sprouts and onions in the skillet, stirring to coat them evenly with butter. Add a pinch of salt and black pepper, then stir occasionally for 2 minutes.

Transfer the skillet to your preheated oven and roast the vegetables until they are golden brown and tender, taking 15 to 20 minutes. Serve hot, garnished with lemon wedges on the side.