Preheat your oven to 425°F (220°C): Ensuring a hot oven is crucial for achieving that sought-after crispy texture on the Brussels sprouts.
Mix the butter ingredients: In a medium bowl, combine 4 tbsp softened salted butter, 1 1/2 tbsp gochujang sauce, 2 tsp toasted sesame oil, and 1/2 tsp soy sauce. Optionally, add 2 tsp brown sugar and 1 small grated garlic clove. Mix until well combined. This step can be done ahead of time and refrigerated for convenience!
Prepare the Brussels sprouts: On a large sheet pan, spread 12 oz shaved Brussels sprouts in a single layer. Drizzle with 1 tbsp avocado or olive oil and sprinkle with 1/4 tsp salt. Toss well to ensure all the sprouts are evenly coated.
Roast the Brussels sprouts: Place the sheet pan in the preheated oven and roast for 15-20 minutes. Look for the Brussels sprouts to become golden brown and crispy, stirring halfway through for even cooking.
Add the walnuts: Remove the pan from the oven and sprinkle 3/4 cup chopped walnuts over the Brussels sprouts. Return to the oven for an additional 3-5 minutes to toast the walnuts until fragrant and lightly browned.
Combine with cranberries and butter: After roasting, take the pan out of the oven and mix in 1/4 cup dried cranberries, followed by the warmed gochujang butter mixture. Toss until everything is well combined and evenly coated.
Serve immediately and enjoy the fantastic aromas and flavors that will fill your kitchen!