• Boil the pasta. Bring a pot of salted water to a rolling boil. Cook the pasta to al dente, usually 2-3 minutes shy of the box instructions.
• Make the topping. In a small skillet, melt the 2 tablespoons of butter with the sesame oil. Add the panko, gochugaru and sesame seeds and cook for 2-3 minutes, tossing often, until the panko is barely golden brown. Season with salt and set aside.
• Preheat an oven to 425ºF. Lightly grease a 3-quart baking dish and place it on a foil-lined baking sheet.
• Make the bechamel sauce. Melt the butter in a large dutch oven or pot over medium heat. Once the butter is hot and foamy, add the shallots and cook for 2-3 minutes, until softened. Stir in the gochujang, gochugaru, oyster sauce, onion powder, and garlic powder and cook for another 2-3 minutes, stirring often. Sprinkle in the flour and stir well for 2 minutes. Pour in the half and half, whisking it in as you pour, and then bring it to a gentle simmer while stirring. Once the sauce has thickened, stir in the cream.
• Melt in the cheese. Remove the pot from the heat and stir in 3/4 of the cheese a bit at a time until it’s all melted and incorporated. Season the sauce to taste with salt and white pepper. Add the pasta to the pot and toss well to coat. Pour half the pasta into the prepared baking dish, top with the remaining grated cheese, then top with the rest of the pasta. Sprinkle the panko topping over the top.
• Bake. Bake the mac and cheese for 15-20 minutes, or until it's hot and bubbling and the panko topping is golden brown. Remove from the oven and let the mac and cheese rest for 10 minutes before serving.

Storage Instructions

• Storage: Leftovers will last up to 4 days if stored airtight in the fridge. You can also freeze the mac and cheese for up to 3 months. When ready to eat, reheat from frozen in a 350ºF for about 45 minutes. Cover the pan tightly with foil to prevent the pasta from drying out.