Cook the pasta: Boil the pasta for 2 minutes less than package instructions (usually 5-7 minutes). Drain and set aside.
Shred the cheese: While the pasta cooks, shred all cheeses and mix them together in a large bowl.
Make the roux: Preheat oven to 350°F. In the same pot, melt the butter over medium heat. Once bubbling, add salt, black pepper, garlic powder, and smoked paprika, stirring for 30 seconds to bloom the flavors. Stir in soy sauce and Worcestershire sauce.
Add the flour: Turn the heat to the lowest it will go! Sprinkle in the flour and whisk continuously for about 2 minutes to cook out the raw taste. This forms a smooth roux that will thicken the sauce.
Make the sauce: Slowly pour in the evaporated milk, whisking constantly until smooth (like seriously whip the crap out of it). Repeat with the heavy cream, whisking to fully combine.
Incorporate the cheese: Add three-quarters of the shredded cheese in three portions. First ⅓: stir until fully melted. Second ⅓: stir until fully melted. Final ⅓: stir briefly, allowing it to partially melt for a gooey texture.
Combine with pasta: Add the cooked pasta to the cheese sauce, folding until evenly coated.
Bake: Pour the mac and cheese into a 9x13 baking dish. Sprinkle the remaining cheese on top. Bake at 350°F for 30 minutes until golden and bubbly. Broil immediately if needed for a golden top, 3-4 minutes or until the cheese crust is to your liking.
Garnish and serve: Top with chopped chives and serve warm.