Preheat your oven to 450°F and place your oven rack in the center of your oven.

In a large mixing bowl, toss the Brussels sprouts with oil and season with salt and pepper. Spread evenly on two baking sheets in a single layer.

Roast the Brussels sprouts, rotating the baking sheets halfway and flipping the brussels sprouts, until they are charred, about 30 minutes.

In a medium skillet, melt the butter over medium heat. Cook the minced garlic until fragrant and lightly browned.

Add the gochujang, soy sauce, maple syrup, and water to the skillet and mix until combined. Remove from heat and mix in the sesame oil.

Combine the Brussels sprouts and gochujang sauce in a bowl and toss to combine. Transfer to a platter and garnish with green onions and toasted sesame seeds.