Caramelized the onions:

• Heat olive oil and 2 tbsp butter in a large sauté pan over medium heat. Add sliced onions and cook for about 10 minutes, stirring occasionally, until soft and golden.
• Season with a pinch of salt, reduce heat to medium-low and continue cooking for about 20-30 minutes, until onions are caramelized to your desired color. Deglaze with a couple splashes of water as needed.
• Once done, remove caramelized onions from pan and set aside.

Cook the pasta:

• In a large pot, boil pasta according to package directions until al dente. Drain and set aside.

Preheat oven to 350F (180C).

Mix the cheese:

• In a large bowl, combine all shredded cheeses and toss to mix evenly.

Make the sauce:

• In the same pot used for the pasta, melt 3 tbsp butter over medium-low heat. Stir in garlic powder, smoked paprika, Gochujang, soy sauce, Gochugaru (if using), 1 tsp salt, and 1/2 tsp black pepper. Mix well.
• Whisk in the flour and mix until smooth.
• Mix in Gochujang and soy sauce (it’s ok if it turns into clumps), then slowly pour in the milk. Whisk to break up any clumps, then pour in heavy cream and mix until the sauce is smooth and creamy. Bring mixture to a gentle boil, then simmer for 3-4 minutes until it thickens to a gravy consistency.

Add cheese and pasta:

• Remove pot from heat. Stir in 2/3 of the shredded cheese mix and whisk until melted and creamy.
• Add the cooked pasta to the pot and stir until fully coated in the sauce.

Assemble:

• Ladle half of the mac and cheese into the baking dish. Layer all of the caramelized onions evenly on top, then sprinkle with a little more than half of the remaining cheese.
• Add the rest of the pasta, then top with the remaining cheese.

Breadcrumb topping:

• Melt 1 tbsp butter in a small skillet over low-medium heat. Add the breadcrumbs and cook for about a minute, until the breadcrumbs turn golden. Sprinkle over the top of the Mac & cheese.

Bake:

• Bake for 20 minutes, then broil on high for 2-3 minutes, until bubbly and golden on top.

Finish:

• Remove from oven and garnish with some fresh parsley on top. Serve warm & enjoy!