Preheat your oven to 425°F (220°C) and line a baking sheet with parchment paper or foil.
In a large bowl, toss the Brussels sprouts with olive oil, a pinch of salt, and pepper. Spread the sprouts in an even layer on the baking sheet, cut side down.
1 Pound Brussels Sprouts, 1 Tablespoon Olive Oil, Salt and Pepper
Roast for 15-20 minutes, flipping halfway through, until they are golden brown and crispy on the edges.
While the Brussels sprouts roast, add soy sauce, rice wine vinegar, brown sugar, garlic, ginger paste, and red pepper flakes to a small saucepan. Combine water and cornstarch and add to the sauce ingredients. Bring the sauce to a low simmer, stirring occasionally, until the sugar dissolves and the mixture begins to thicken.
¼ Cup Soy Sauce, 2 teaspoons Rice Wine Vinegar, 2 Tablespoons Brown Sugar, 1 Clove Garlic, ½ teaspoon Ginger Paste, ⅛ teaspoon Red Pepper Flakes, 1 ½ teaspoon Cornstarch, ¼ cup Water
Transfer the roasted Brussels sprouts to a large mixing bowl. Pour the teriyaki sauce over the sprouts and toss to coat evenly.
Serve immediately, garnished with sesame seeds or green onions, if desired.