Remove the base of the brussels sprout by cutting off just the very bottom part of the stem (it’s white). If you cut too much off, the leaves will fall apart, so be careful. Slice the brussels sprouts in half.

In a small saucepan add the orange zest, orange juice, ginger, garlic, vinegar, soy sauce, honey, brown sugar, and red pepper flakes and let the sauce reduce by half. About 6 - 8 minutes.

Meanwhile, place a large pan on medium high heat and add the brussels sprouts to the pan, cut side down. Drizzle with the butter and gently push the brussels sprouts around in the pan, keeping them cut side down. You might need to do it twice depending on how many you can fit in your pan at one time. After about 6 minutes, when the brussels sprouts have browned slightly on the cut side and the pan is hot, pour half of the reduced sauce in with the brussels sprouts and let cook for just a few seconds. Pick the pan up with the handles and shake around to let the sauce mix throughout. Move brussel sprouts to a serving bowl and drizzle with the remaining glaze. Serve warm.